Ontario Provincial Police have used an emergency provision that circumvents the normal need for court approval of telephone wiretaps three times since 2002, including in the case of Mohawk protesters who set up blockades in Eastern Ontario during last summer's Aboriginal Day of Action, a spokesman for the force said Thursday.

In this June 29, 2007 photo, Mohawk protest leader Shawn Brant is seen speaking with an elder during a blockade near Deseronto, Ont. (Tom Hanson/Canadian Press)The OPP is facing calls for an outside investigation after the CBC revealed the force wiretapped the phones of four people — Mohawk protest leader Shawn Brant, two friends and his brother, a lawyer who was not involved with the blockades — without judicial approval.

Under section 184.4 of the Criminal Code, police can act on their own in extreme emergencies if they suspect the targets of the surveillance are about to commit serious crimes.

OPP Insp. Dave Ross said the decision to use the provision is not taken lightly.

"Certainly, there's a fairly extensive evaluation that's undertaken prior to any decision being made to utilize that provision that grants us that authority under the Criminal Code," Ross told CBC News. "And during all those instances, we've exercised reasonable diligence and used it only in urgent circumstances."

Ross did not have information on the two other occasions the provision was used, or whether those cases resulted in evidence presented at a trial where a judge could review the procedure.

"Certainly, it's never done with the purpose of intelligence gathering," he said.

The June 29, 2007 protests by Brant's group prompted police to close Highway 401 and CN to halt traffic on the Montreal-Toronto corridor on one of the busiest holiday weekends of the summer.

Critics have said the police force's wiretaps during the protests were illegal, since there were numerous warnings about the protests several days in advance.

No role in wiretapping decision: Fantino

The wiretaps feature heated discussions between Brant and OPP Commissioner Julian Fantino, in which Fantino told Brant "your whole world’s going to come crashing down" if Brant did not order aboriginal protesters to withdraw from blockade sites.

During his testimony at Brant's pre-trial hearing last August, Fantino said he gave Brant a deadline, and was prepared to move in if the protesters didn't lift the blockades. He said he believed the public interest demanded that the highway be reopened.

Fantino also said he had no role in the decision to wiretap the calls.

Det.-Const. Douglas Weiss, the lead investigator in the Brant case, also testified at Brant's pre-trial hearing that he had never heard the wiretaps and never asked for them to be included as evidence. Weiss said he was told there was nothing of interest in the tapes.

He also said the OPP only decided they would disclose the existence of the wiretaps a week before Brant's pre-trial hearing began.