OTTAWA—The Supreme Court of Canada struck down a law that gives police warrantless wiretap powers to prevent an emergency, saying it provides no accountability or oversight mechanism.

The unanimous judgment issued Friday gave Parliament 12 months to re-write the law. In the meantime, the 1993 Criminal Code (Section 184.4) — the only wiretap provision that does not require after-the-fact notification either to the person wiretapped or some kind of report to Parliament — remains in force.

The decision doesn’t pose a risk to public safety while Parliament rewrites the notice provision, said lawyer Joe Wilkinson, counsel to the Criminal Lawyers Association of Ontario, which intervened in the case.

It is still open to police to intercept private communications to prevent emergency situations but “they would do well to give some kind of notice to whomever it is ended up getting intercepted,” he said.

Wilkinson said there have only been a few superior court rulings on the power, and police were working “very much in the dark” as to its proper use.

Now, he said, “the police still have the bulk of the section and they’ve got it with some really good guidance from the top court in the land.”

The country’s top court, ruling in a 2006 drug-related kidnapping case, said most of the law “passes constitutional muster.”

Police may only use the authority if they believe “on reasonable grounds” that the situation is so urgent, a judge’s authorization could not be obtained under another provision. But it was deemed unconstitutional because “unless a criminal prosecution results, the targets of the wiretapping may never learn of the interceptions and will be unable to challenge police use of this power.

The unanimous ruling was the first written by rookie judges Michael Moldaver and Andromache Karakatsanis.

Lawyer Neil Mackenzie, communications counsel for the B.C. attorney general ministry’s criminal law branch, said the high court recognized that urgent “life and death” situations do arise, and that unauthorized emergency interceptions may be necessary.

“The primary concern really is the issue of notice and there are legislative changes underway that should address those issues,” he said.

Justice Minister Rob Nicholson was not available to comment, nor was the federal government’s lawyer, Cheryl Tobias, who argued the case.

“We will be reviewing the court’s decision carefully to determine next steps. It would be inappropriate to comment further at this time,” said Nicholson’s spokesperson, Julie Di Mambro, in an emailed reply.

It does not affect the conviction of six people jailed in the kidnapping of Peter Li, his wife Jennifer Pan and their friend Xiao Chang. However, they have appealed and argued that the tainted wiretap evidence should not have been admitted at trial.

The offenders — Yat Fung Albert Tse, Nhan Trong Ly, Viet Bac Nguyen, Huong Dac Doan, Daniel Luis Soux and Myles Alexander Vandrick — were convicted and got lengthy jail terms ranging from 10 to 18 years.

Ken Westlake, lawyer for Doan, doubted Friday’s decision would have a significant impact on the offenders’ ongoing challenge to their conviction.

But he said he was “heartened” the high court supported the principle for judicial approval over wiretaps. “That important principal has started to be slightly eroded in these conservative times of tough-on-crime.”

He said the rewritten law should require not just notice to targets, but also reports to Parliament — although the Supreme Court left it up to lawmakers.

“I think it’s a really important thing for Parliament and a supervisory committee to keep track of when, how, how often and in what circumstances this stuff is going on,” said Westlake. “Right now nobody has any idea how often this is used.”

Using the emergency unauthorized interception powers outlined in Section 184.4 of the Criminal Code, police began immediately intercepting the private communications of Peter Li’s daughter after she notified them of the kidnapping. Her father had been allowed to call her to relay the $10-million ransom demand.

The emergency wiretap provision allows interceptions without prior judicial authorization where the police believe it is “immediately necessary to prevent an unlawful act that would cause serious harm.”

It also requires police to begin the process of seeking a warrant, which in this case, they got 24 hours later.

The victims were held for 25 days, beaten and Tasered before being released by their captors, who ultimately picked up $1.3 million in ransom drops.

The trial judge found the warrantless intercept a breach of Section 8 of the Charter, which protects individuals from unreasonable search and seizure. He later admitted the evidence, under Section 24, saying it would not bring the administration of justice into disrepute.

Lawyer Chris Wayland, who intervened on behalf of the Canadian Civil Liberties Association, said no one in the case argued emergency powers are unnecessary, yet he welcomed the court’s demand for accountability.

“Previously you could have a warrantless wiretap set up on your phone and never be told about it, and you’d never know that it had ever been done,” he said. “The court was quite clear today that’s a dangerous thing to have in a free society.”

Wayland also suggested the ruling potentially has implications for Bill C-30, the federal Conservative government’s proposal to demand, without a warrant, subscriber information from Internet Service Providers. Wayland said Section 17 of the bill does not include any requirement — if no charges result — for police to notify a person after the fact that their information had been obtained.