What is the Public Interest Defence?
The Public Interest Defence protects a publisher against a defamation claim if the publisher proves that the material concerned an issue of public interest and that the publisher reasonably believed its publication was in the public interest. In Queensland, the defence is in section 29A of the Defamation Act 2005 (Qld). It can apply even if a defamatory allegation cannot be proved substantially true, but a serious subject alone does not make publication reasonable.
The court looks at the actual publication and the circumstances in which the decision to publish was made. The quality of the information, the seriousness of the allegation, the opportunity to respond and the way the story was presented can all matter. A journalist, a community organisation or an individual posting online may invoke the defence; none receives automatic protection merely by calling a story public interest journalism.
How the Public Interest Defence works
Under section 29A(1), the defendant must establish two statutory requirements. First, the matter concerned an issue of public interest. Secondly, the defendant reasonably believed that publication of the matter was in the public interest. The second requirement has both a genuine belief and an objective reasonableness component. The defendant carries the burden of establishing the defence.
These questions should be kept separate. An investigation into patient safety plainly may concern an issue of public interest. That does not answer whether a publisher had a reasonable basis to publish a particular accusation against a particular surgeon, in the form and circumstances chosen.
The Queensland provision commenced on 1 July 2021, and section 50 makes the 2021 amendments applicable to defamatory matter published after commencement. Comparable provisions operate under the uniform defamation reforms in other Australian jurisdictions, but commencement dates and the applicable law need checking. This article uses Queensland law; the Federal Court cases discussed below applied the equivalent New South Wales provision.
The defence has an English statutory antecedent, but the Queensland Act supplies the governing test. English provisions and older qualified privilege cases can provide useful background; their wording and requirements should not simply be treated as Queensland law. Justice Lee discusses that history in Russell at paragraphs 305–308.
What counts as an issue of public interest?
Public interest is broader than government or politics. Patient safety, the conduct of public officials, the administration of justice, financial misconduct affecting the community and serious workplace safety concerns can all raise issues of public interest. A matter may affect a particular community rather than the whole country.
Public curiosity is a different thing. A person’s private relationship, a personal feud or embarrassing conduct does not become a public interest issue simply because it attracts attention online. The question is whether the publication concerns an issue in which the community has a legitimate interest; the answer depends on its content and context.
Does the publisher have to prove the allegation is true?
No. The Public Interest Defence is distinct from substantial truth under section 25. A defendant may be unable to prove the defamatory imputations substantially true yet establish a reasonable belief that publication was in the public interest. That is not a licence to ignore whether information is reliable. A weak source, contradictory documents or a misleading presentation may undermine the reasonableness of the belief.
The defence is directed to belief in the public interest of publishing the matter, not a separate statutory requirement that the defendant believed every allegation was true. What the publisher believed about the accuracy and reliability of the information is nevertheless often central evidence.
What courts consider under the Public Interest Defence
Section 29A(2)–(4) requires the court to consider all circumstances and gives a non-exhaustive list of possible factors. Not every factor must be considered in every case, and none operates as an automatic pass or failure.
| Factor | Why it matters |
| Seriousness and presentation | The more damaging the imputation, the closer the scrutiny may be. Does the publication distinguish allegation, suspicion and established fact? |
| Sources and verification | Who supplied the information, how reliable were they, and what independent checks were possible? A confidential source may have a good reason for anonymity. |
| Response | Did the publication include the substance of the person’s side, or was a reasonable attempt made to obtain and publish it? |
| Timing and public function | Was prompt publication in the public interest? Did the material relate to the person’s public functions or activities? |
| Freedom of expression | The court may consider the importance of discussion of public interest issues alongside the other circumstances. |
The focus is the reasonableness of the belief, not a stand-alone audit of whether every step in the publisher’s conduct was reasonable. Conduct remains evidence from which the court can assess that belief. A substantial investigation can support it; ignoring an obvious contradiction can damage it. The court makes an overall judgment rather than awarding points for completing a checklist.
Editorial judgment has a place in this assessment. In Russell at paragraphs 336 and 347, Justice Lee recognised that appropriate allowance may be made for editorial decisions, while rejecting a sliding scale under which a more important topic automatically permits more error. A court still evaluates the complete circumstances.
The opportunity to respond
A meaningful request for comment identifies the substance of the allegations and gives a reasonable opportunity to answer in the circumstances. Sending a vague question shortly before publication may achieve little. So may omitting a response that directly addresses the central accusation while saying the person declined to comment.
There is no universal statutory minimum period for a response and no rule that a missing response defeats the defence in every case. Urgency, the nature of the allegation, previous communications and the reasons a response could not be obtained all matter. Keep the correspondence and the reason for the deadline: those records may be more persuasive than a later reconstruction.
Confidential sources and verification
A source may need anonymity for a sound reason, including fear of retaliation. Confidentiality does not itself establish reliability. A careful publisher should consider what the source actually knows, whether they have a stake in the dispute, what documents support the account and whether an independent person can verify the significant points.
Promising confidentiality also raises a practical litigation problem. A publisher should obtain legal advice before making promises it may be unable to maintain, and preserve the underlying records securely. Source-protection questions depend on the applicable evidence law and circumstances; they should not be treated as automatically resolved by the Public Interest Defence.
Public Interest Defence case examples
Russell v ABC: a public interest subject was not enough
In Russell v Australian Broadcasting Corporation (No 3) [2023] FCA 1223, former commando Heston Russell sued over ABC publications concerning allegations involving Australian special forces in Afghanistan. Justice Lee accepted that the publishers believed publication was in the public interest, but held their belief was not reasonable. The Public Interest Defence failed; the court awarded $390,000 in general damages, plus interest.
One important problem concerned a freedom of information response. The judge accepted it confirmed an active investigation, but found it could not reasonably or safely be treated as confirming that the investigation concerned November Platoon. The distinction between evidence of an investigation and evidence identifying its subject mattered. The decision illustrates why a serious public issue does not allow a publisher to convert an uncertain inference into a confirmed fact.
Al Muderis v Nine: an extensive investigation supported the defence
In Al Muderis v Nine Network Australia Pty Limited (Trial Judgment) [2025] FCA 909, a surgeon sued over a television broadcast, articles and video concerning his practice and patient experiences. Justice Abraham dismissed the claim, finding that the publishers established both contextual truth and the Public Interest Defence for the relevant publications.
The court identified a strong public interest in informing prospective patients about negative experiences with a complex surgical procedure. The journalists had spoken to a broad range of sources and reviewed extensive documents. They also excluded some allegations they considered insufficiently supported or not in the public interest. The judge held that errors do not necessarily defeat the defence: the whole investigation and the information available to the publishers mattered.
This was a trial judgment and was appealed. Its treatment should be read subject to the appeal and any subsequent orders. It does not mean that every medical complaint can safely be published, or that a lengthy investigation cures a misleading allegation.
Practical examples of the Public Interest Defence
The following examples are hypothetical. They show how small changes in evidence and wording can alter the assessment; they are not predictions of a court’s decision.
A local council procurement allegation
A local reporter obtains tender documents and interviews several people about a council contract. The documents raise a legitimate question about whether the declared selection process was followed. The reporter puts the specific concerns to the council officer, checks the response against the records and reports the dispute as an allegation, identifying what remains unresolved.
The public spending issue and the recorded verification may support the Public Interest Defence. The position becomes harder if the headline says the officer “stole public money” when the underlying evidence only raises questions about a procurement decision. A technically careful paragraph may not undo the meaning conveyed by the headline and story taken together.
A community group posts a safety warning
Residents hear that a childcare worker has been investigated for harming a child. One parent posts the worker’s photograph in a public group and says the worker is dangerous. The post relies on one second-hand account; the parent has not checked whether the worker was the person investigated or sought a response.
Child safety is plainly capable of being a public interest issue. On those assumed facts, however, the publisher faces serious difficulties establishing a reasonable belief in the public interest of publishing this particular accusation. An urgent, targeted report to an appropriate authority may raise different legal questions from a public accusation. Neither course is automatically protected.
Who can use the Public Interest Defence?
Section 29A is not confined to professional journalists. A blogger, employee, campaigner or member of the public can seek to establish the Public Interest Defence. The same statutory questions apply, although the circumstances and resources of the publisher may differ.
Not naming someone does not necessarily avoid a claim. A role, photograph or local context may allow recipients to recognise them. Our guide to identification in defamation when a person is not named explains what a claimant must establish and the evidence that may matter.
Public Interest Defence compared with other defences
| Defence | Central question |
| Public interest — s 29A | Did the matter concern an issue of public interest, and did the defendant reasonably believe publishing it was in the public interest? |
| Substantial truth — s 25 | Can the defendant prove the defamatory imputations are substantially true? |
| Contextual truth — s 26 | Are there substantially true contextual imputations which mean the remaining imputations do not further harm the plaintiff’s reputation? |
| Qualified privilege — s 30 | Did the recipient have the relevant interest, was the information given in that course, and was the publisher’s conduct reasonable? |
| Honest opinion — s 31 | Was the matter an opinion rather than a statement of fact, on a matter of public interest, based on proper material, subject to the statutory conditions? |
The precise conditions differ. Section 30 asks whether the defendant’s conduct was reasonable and addresses malice. Section 29A instead focuses on reasonable belief about publication. For opinion, see section 31 and our guide to the defence of honest opinion in defamation. Our explanation of contextual truth in defamation examines the separate issues under section 26.
A defendant may advance alternative defences where the facts support them. Pleading truth, however, can widen the factual dispute and require proof of the imputations. A publisher should decide what evidence is actually available before assuming that every defence is worth running.
How to prepare a Public Interest Defence
Preserve the complete publication, including headlines, images, links, captions, versions and the context in which the audience saw it. Keep the material available before publication: source notes, documents, recordings, verification checks, drafts, requests for comment and responses. Record when information was received and who made the publication decision.
The distinction between evidence available before publication and information discovered later is important. Later evidence may be relevant to issues in the case, but it should not be presented as the basis for a belief held before the publisher knew it. Avoid deleting inconvenient drafts or correspondence. Seek advice before circulating a legal assessment, because confidentiality and privilege require care.
If the material remains online and significant new information undermines its basis, reassess it promptly. In Al Muderis, the judge considered whether a material change could affect an ongoing publication and concluded that the defence had not been lost on the facts. Correction, qualification or removal may be appropriate depending on what has changed; later disagreement alone does not automatically extinguish the defence.
What if you are the person defamed?
Identify the specific meanings conveyed, who received the material and the evidence of reputational consequences. Section 10A requires serious harm, or likely serious harm, to reputation; the issue is separate from any defence. Our guide to the serious harm threshold in defamation explains the evidence and procedure in more detail.
A public interest topic should not deter a claimant from examining the publication closely. What was the source for the accusation? Did the publisher distinguish suspicion from fact? Was a response fairly sought and accurately included? On the other hand, an error in a publication does not automatically defeat a Public Interest Defence.
In Queensland, section 12A and section 12B govern concerns notices and the conditions for commencing proceedings, subject to the statutory exceptions. The guide to sending a concerns notice explains the process. Act promptly: limitation periods and their statutory extensions require separate assessment, and a notice should not be treated as an indefinite pause on a claim.
Pleadings, disclosure and evidence
If the dispute proceeds, the pleaded imputations and the particular matter complained of frame the contest. The defendant must articulate the basis of the Public Interest Defence, and the claimant should identify the factual grounds on which it is disputed. Each side should be ready to address the documents and witnesses necessary to prove those positions.
In Queensland court proceedings governed by the Uniform Civil Procedure Rules, the timing of pleadings can affect disclosure obligations. Our guide to when pleadings close in Queensland explains the ordinary position and its qualifications. Federal Court proceedings follow different rules and case-management orders; do not assume the Queensland timetable applies there.
For a publisher, the difficult question is often not whether the topic mattered. It is whether the material available at the time justified a belief that publishing this account, about this person, in this form was in the public interest. For a claimant, testing that proposition requires attention to the whole publication and the investigation behind it, not just the most offensive sentence.
