Drawing parallels to the charges brought against CIA operatives by a Milan magistrate last week, attorney Marlys Edwardh said Canadian law defined torture as illegal wherever it occurs. Arar, 34, was seized by U.S. agents while he was changing planes in New York, questioned for 12 days and then transported in shackles to Syria.

"Torture is a crime that is triable by Canadian courts if the victim is a Canadian citizen. The Americans definitely aided and abetted this crime," Edwardh said, standing outside the site of a judicial inquiry into Arar's treatment.

Arar's attorneys said they would call for a criminal investigation of Canadian authorities for their role in Arar's transfer to Syria and his interrogation there, which Arar said included beatings and more than 10 months of confinement in a coffin-size dungeon.

Testimony given during the inquiry this week described extensive and highly organized involvement with Syria by both Canadian and U.S. officials, which was ongoing by 2002. According to the testimony, those involved included Canadian legal advisers, diplomats and members of the CIA and FBI, all of whom regularly approved giving the Syrians intelligence and other information to be used in interrogations.

"I was very surprised that what seems to be in place is a mechanism for fairly routine sharing of important information" with Syria, Edwardh said after the testimony ended. "We are exposing people to the risk of torture while offering to work with those regimes. It's shocking. It shouldn't happen."

The judicial inquiry was convened after Arar was released without charges by Syria and returned to his wife and children in Canada in October 2003. The computer engineer has denied any involvement in radical politics and called for Canadian officials to be held accountable for his treatment.

A key witness at the inquiry, Michel Cabana, the superintendent of the Royal Canadian Mounted Police, denied in testimony Wednesday and Thursday that Canadian authorities knew the Americans had decided to send Arar to Syria instead of back to Canada. Arar, who came to Canada at age 17, holds dual citizenship.

"This is not something I even considered as something the Americans could even do," Cabana testified Thursday. "I did not believe their laws would allow them to do that."

But Cabana acknowledged sending a list of questions to U.S. agents to pose to Arar. He repeatedly said Arar was not a target of investigation but knew some men who were.

Cabana also described frequent formal meetings he had with many different U.S. and Canadian agencies to coordinate their work after the Sept. 11, 2001, attacks and the lifting of restrictions on trading investigative information. One meeting in 2002 included a PowerPoint presentation on suspects to U.S. law enforcement agents.

Arar and his supporters have said that information was often flawed and included fabrications derived from torture sessions. Three Arab Canadian men have been interrogated in Syria and released without charges. By mid-August 2002, a month before Arar was detained at John F. Kennedy International Airport, one of the other Canadians, Ahmad Abou El-Maati, had complained to consular officials of torture.

Minutes of a meeting of Cabana's anti-terrorism unit in Ottawa in August 2002 indicated the participants' wariness about the potential public reaction.

The meeting discussed "media lines to be used when an individual's allegations about torture in Syrian authorities" were made public, the memo introduced to the inquiry read. "The attending agencies all are agreed that minimal information will be put out due to the ongoing police investigations."

Arar watched the proceedings Thursday with his 8-year-old daughter. He said what happened to him should be chilling to all Canadian citizens.

"This can affect every Canadian traveling, especially Muslim men," he said. "You are stopped, and they can't charge you with anything, but they send you off to another country to be tortured."

"Are there any controls on these people?" he asked, referring to authorities. "Is this the way to fight terrorism -- by abolishing due process, by abolishing justice?"

The judicial inquiry is scheduled to conclude with separate public and classified reports by year's end. The testimony and documents in evidence are full of blacked-out redactions of information that the government claims would jeopardize national security.