Prosecutor’s Duty of Disclosure

In New South Wales, the Prosecutor’s Duty of Disclosure is governed by Prosecutorial Guideline 18 of the NSW Office of the Director of Public Prosecutions (“DPP”), which states:

“Prosecutors are under a continuing obligation to make full disclosure to the accused in a timely manner of all material known to the prosecutor which can be seen on a sensible appraisal by the prosecution:

•           to be relevant or possibly relevant to an issue in the case;

•           to raise or possibly raise a new issue whose existence is not apparent from the evidence the prosecution proposes to use; and/or

•           to hold out a real as opposed to fanciful prospect of providing a lead to evidence which goes to either of the previous two situations.     

The prosecution duty of disclosure does not extend to disclosing material:

•           relevant only to the credibility of defence (as distinct from prosecution) witnesses;

•           relevant only to the credibility of the accused person;

•           relevant only because it might deter an accused person from giving false evidence or raising an issue of fact which might be shown to be false; or

•           of which it is aware concerning the accused’s own conduct to prevent an accused from creating a trap for himself or herself, if at the time the prosecution became aware of that material it was not seen as relevant to an issue in the case or otherwise disclosable pursuant to the criteria…”

The Commonwealth DPP and other states of Australia also have disclosure policies.

 The proper role of the prosecutor, contrary to popular perception, is not that of a partisan persecutor bent on securing the conviction of an accused person, but rather that of a quasi judicial 'minister of justice' whose detached function is to seek justice and to ensure fairness. The fundamental theme that emerges in relation to the issue of disclosure is that the prosecutor must act as the frank minister of justice.  

 However, Hinton[1] has noted:

 “The tension inherent in being both adversary and minister of justice renders it imprudent to leave the prosecutor with the power to decide what unused material should or should not be disclosed where that decision requires an assessment of the qualitative nature of the material to the defence.”[2] 

Grey v R[3] stands as authority for the proposition that the prosecution must at common law also disclose all relevant evidence to an accused, and that a failure to do so may, in some circumstances, require the quashing of a verdict of guilty.[4]

 An example of the prosecutor acting as an adversary for the Police and on having a ‘suspect focus’ due to the outcry of the general public is the High Court decision of Mallard v R (2005) 222 ALR 236. The appellant, Andrew Mallard was tried and convicted by the Supreme Court of Western Australia of the murder of Mrs Lawrence, the proprietor of a jewellery shop at Perth on 23 May 1994. It was ascertained at the hearing, the police and prosecution were in the possession of evidence before and during the trial that had not then been disclosed to the appellant. The case raised critical systemic problems of disclosure, for example the police, in respect of a number of the witnesses, including only amended statements in the brief, and not previous versions, which would have given important information to the defence.

It was held per curiam, the non-presentation of the evidence and its significant forensic value resulted in a substantial miscarriage of justice. The verdict was quashed.[5]

Kirby J illustrated the non-disclosure of evidence as follows: “[I]t is important to consider the cumulative effect of the non-disclosure or suppression of material evidence in the hands of the police and thus available to the prosecution. It is the cumulation, variety, number and importance of such evidence that is critical to my conclusion that a miscarriage of justice occurred in the appellant's trial. [The non-disclosure of evidence included]: … The pig’s head experiment … The salt-water experiment …. The missing cap … The undisclosed sketches … The locking of eyes … The man wearing a bandana …”[6]

In relation to the Prosecition Guidelines, “[T]he unprovided and suppressed materials did not fall into .. [clauses 61 to 64 of the Prosecution Guidelines]. Without exception, they were statements procured in the preparation of the police brief for ultimate tender to the prosecutor. At least some of them were certainly known to the prosecutor. All of them would have been available to the Director of Public Prosecutions.”[7] Kirby J commented that the DPP guidelines, despite having the status of a statutory instrument and, in theory, prevailing over the common law, were not designed to exclude the operation of the common law.[8] Rather they 'were intended to express, clarify, elaborate and make public the 'longstanding prosecution policy' that had developed conformably with the common law.'[9]

The body of unpresented evidence in Mallard “was potentially highly significant in two respects. The first lay in its capacity to refute a central plank of the prosecution case with respect to the wrench. The second was its capacity to discredit, perhaps explosively so, the credibility of the prosecution case, for the strength of that case was heavily dependent on the reliability of the confessional evidence, some of which was inexplicably not recorded, although it should have been recorded.”[10]

In relation to the prosecutor’s duty of disclosure, Kirby J stated “[T]his court will not second guess the prosecutor in the decisions that have to be made in presenting the prosecution case. Still less is the prosecutor burdened with an obligation to present the defence case (which, in any event, may not always be known in advance of the trial). The obligation imposed by the law is to ensure a fair trial for the accused, remembering the special requirements that descend upon a prosecutor, who represents not an ordinary party but the organised community committed to the fair trial of criminal accusations and the avoidance of miscarriages of justice.”[11]

In conclusion, it is the prosecutor’s duty of disclosure as per Guideline 18 and case law highlight the importance, as the prosecutor is the minister of justice in search of the truth for either the police or the accused, and any departure of this that does not fall within the exceptions, will result in a one sided presentation of evidence before the Court most likely resulting in a miscarriage of justice.


[1] Hinton, M, 'Unused Material and the Prosecutor's Duty of Disclosure' (2001) 25 Crim LJ 121.

[2] Ibid at 134.

[3] (2001) 184 ALR 593; 75 ALJR 1708;  [2001] HCA 65

[4] Mallard v R (2005) 222 ALR 236 at [17].

[5] Per Gummow, Hayne, Callinan and Heydon JJ at [42] and [86].

[6] Mallard at [56].

[7] Mallard at [62].

[8] Mallard at [63].

[9] Mallard at [63].

[10] Mallard at [23].

[11] Ibid at [82].

If you seek further legal advice on this issue or need a lawyer, please do not hesitate to contact John Fasha by email to or by telephone (02) 9610 6677 or 0450 217 901.