Informer Privilege in Canadian Criminal Law: What Defence Can and Can’t Challenge

Informer privilege is one of the most protected categories of evidence in Canadian criminal law. The privilege exists to protect the identity of people who provide information to police on the understanding that their identity will not be disclosed. Without that protection, the entire confidential informer system collapses and serious investigations become impossible. The Supreme Court of Canada has described informer privilege as near-absolute and has identified only a single, narrow exception: innocence at stake. This guide walks through what informer privilege actually is, why it is so heavily protected, and how the innocence at stake exception works.

What is Informer Privilege Under Canadian Law?

Informer privilege is a common-law rule of evidence that protects the identity of confidential informers from disclosure. The rule applies in criminal proceedings, civil proceedings, and to police investigations more broadly. Where the privilege attaches, no one (not the Crown, not the police, not the court) can disclose anything that would tend to identify the informer. The identity is protected even from the accused.

The justification for the privilege is policy-driven. Confidential informers provide essential information for criminal investigations, particularly in drug, organized crime, and gang files. They do so on the understanding that their identity will be protected. If informers can be identified through court proceedings, they face retaliation, violence, or death. They will stop coming forward. Police lose a critical investigative tool. The Supreme Court of Canada in R v Leipert described the rule as “of fundamental importance to the workings of the criminal justice system.”

Once the privilege attaches, it covers more than just the informer’s name. It covers anything that would tend to identify the informer (the time, place, and circumstances of contact with police, the content of what was said, anything in the disclosure that would narrow down who the informer might be). This is what makes the privilege so robust and so frustrating from a defence perspective.

The Leipert Rule: Why Informer Privilege is Near-Absolute

The leading Supreme Court of Canada decision on informer privilege is R v Leipert, [1997] 1 SCR 281. The accused in Leipert was charged with possession of marijuana for the purpose of trafficking. The search of the residence was based on information from a Crime Stoppers tip. The accused sought disclosure of the tip and the identity of the tipster to challenge the search warrant. Crown asserted informer privilege.

Justice McLachlin (as she then was) wrote for a unanimous court that informer privilege is subject to only one exception: innocence at stake. Outside that exception, the privilege is absolute. The court emphasized several key principles:

• The privilege attaches automatically wherever a person provides information to police on a promise (express or implied) of confidentiality
• The privilege belongs to the Crown and to the informer; neither can unilaterally waive it without the consent of the other
• The trial judge has no discretion to override the privilege except where innocence at stake is established
• The court has a duty to give effect to the privilege even where the accused has not specifically asserted the privilege issue

Leipert closed off most of the avenues that defence had previously used to challenge informer-based investigations. It became the operating rule for confidential informer files in Canadian criminal courts, including in BC.

Innocence at Stake: The Only Way to Pierce Informer Privilege

The single exception to informer privilege is the innocence at stake exception. Where the accused can show that the identity of the informer is necessary to establish innocence (in the sense that without the disclosure there would be a real risk of wrongful conviction), the privilege can be set aside.

The threshold is high. The accused must establish, on the available evidence, a basis to conclude that disclosure of the informer’s identity is necessary to demonstrate innocence. Mere speculation is not enough. Tactical advantage to defence is not enough. The accused has to show that the trial cannot be fair without the disclosure.

Categories of cases where innocence at stake has succeeded include:

• Cases where the informer is alleged to be the actual perpetrator of the offence and the accused is a wrongly identified party
• Cases where the informer’s identity is necessary to demonstrate that the accused was framed or set up
• Cases where the informer’s evidence is the central piece of the Crown’s case and the credibility of the informer cannot be assessed without identification

The procedure for raising innocence at stake is itself heavily protected. The application is heard in camera (closed court). The accused does not see materials that would tend to identify the informer. The court makes a finding on whether the threshold has been met before any disclosure occurs. Where the threshold is met, the court orders only the minimum disclosure necessary to address the innocence at stake concern.

Confidential Informer vs Police Agent: The Critical Distinction

The category of person who attracts informer privilege is the confidential informer (CI). The CI is someone who provides information to police on the understanding of confidentiality but who does not act on police instructions during the investigation. The CI gives the tip and steps back.

A police agent is different. An agent is someone who acts on police instructions during the investigation. The agent participates. The agent records, interacts with the accused, or carries out a transaction. The agent provides Crown with affirmative evidence at trial.

The distinction matters because police agents do not attract informer privilege. The agent’s identity must be disclosed. The agent’s evidence is open to cross-examination. The agent can be called as a Crown witness, and where Crown does call the agent, the defence can run the cross-examination that the privilege would have foreclosed.

Where the line between CI and agent falls is itself a litigable issue. A person who started as a confidential informer can cross the line into being an agent through the course of the investigation. The Supreme Court of Canada has said that the question is whether the person was acting on the instructions of the police at the time of the relevant conduct. Defence applications challenging an “informer” classification on the basis that the person was actually an agent are a regular feature of drug and organized-crime files.

Section 37 of the Canada Evidence Act and the Procedure for Informer Privilege Claims

Where Crown asserts informer privilege over specific material in a criminal proceeding, the procedural framework is set out in Section 37 of the Canada Evidence Act. The provision allows a public officer (or Crown) to object to the disclosure of information on the ground that it would be injurious to a specified public interest. Informer privilege is one of the public interests covered.

The Section 37 procedure involves an in camera hearing before the trial judge, with the affected material reviewed by the judge in sealed format. The accused is excluded from the in camera portion. The court then decides whether the public interest in non-disclosure outweighs any countervailing interest in disclosure, applying the Leipert rule and the innocence at stake exception.

The Section 37 hearing produces a ruling that becomes part of the record. Where the ruling goes against the accused, it can be appealed only on narrow grounds. Where it goes in favour of the accused (a finding of innocence at stake), the disclosure ordered is typically minimal and tightly tailored.

Contact Julian Van Der Walle Law

If you are facing a criminal charge in BC where the Crown’s case relies on confidential informer evidence, the defence work involves identifying every issue available at the margins of the privilege. Julian represents clients across Vernon, Kelowna, Penticton, Salmon Arm, and the Kootenays. The first consultation is free.