The United States "very likely" sent a Canadian software engineer to Syria, where he was tortured, based on the false accusation by Canadian authorities that he was suspected of links to Al Qaeda, according to a new government report.

Syrian-born Maher Arar was exonerated of all suspicion of terrorist activity by the 2 1/2-year commission of inquiry into his case, which urged the Canadian government to offer him financial compensation. Arar is perhaps the world's best-known case of extraordinary rendition -- the U.S. transfer of foreign terror suspects to third countries without court approval.

"I am able to say categorically that there is no evidence to indicate that Mr. Arar has committed any offense or that his activities constitute a threat to the security of Canada," Justice Dennis O'Connor said Monday in a three-volume report on the findings of the inquiry, part of which was made public.

Arar was traveling on a Canadian passport when he was detained at New York's Kennedy Airport on Sept. 26, 2002, on his way home from vacation in Tunisia.

Arar said U.S. authorities sent him to Syria for interrogation as a suspected member of Al Qaeda, a link he denied.

He spent nearly a year in prison in Syria and made detailed allegations after his release in 2003 about extensive interrogation, beatings and whippings with electrical cables.

O'Connor criticized the U.S. and recommended that Ottawa file formal protests with both Washington and the Syrian government over Arar's treatment.

"The American authorities who handled Mr. Arar's case treated Mr. Arar in a most regrettable fashion," O'Connor wrote. "They removed him to Syria against his wishes and in the face of his statements that he would be tortured if sent there. Moreover, they dealt with Canadian officials involved with Mr. Arar's case in a less than forthcoming manner."

The U.S. is already under intense criticism from human rights groups over the practice of sending suspects to countries where they could be tortured.

U.S. and Syrian officials refused to cooperate with the Canadian inquiry.

The commission found the Royal Canadian Mounted Police shared information about Arar with American anti-terrorist agencies both before and after he was detained.

The RCMP asked the U.S. to put Arar on a watch list as an "Islamic extremist individual" suspected of links to the Al Qaeda terrorist movement, the report said.

The request was issued after Arar met with another man who was under surveillance, a meeting Arar has said was about how to find inexpensive computer equipment.

"The RCMP had no basis for this description, which had the potential to create serious consequences for Mr. Arar in light of American attitudes and practices," the report said.

The RCMP described Arar as the "target" of a domestic anti-terrorist investigation in Canada when in fact he was a peripheral figure who had come under suspicion only because he had been seen in the company of the man who was under surveillance, the report found.

O'Connor said that much of the material shared with U.S. authorities had not been double-checked to ensure its accuracy and reliability -- a violation of the RCMP's usual rules for divulging information to foreign agencies.

O'Connor concluded that the inaccurate information passed by Canadian police to U.S. authorities "very likely" led to their decision to send Arar to Syria.

"It's quite clear that the RCMP sent inaccurate information to U.S. officials," Arar said at a news conference in Ottawa. "I would have not have even been sent to Syria had this information not been given to them."

"I have waited a long time to have my name cleared. I was tortured and lost a year of my life. I will never be the same," Arar said. "The United States must take responsibility for what it did to me and must stop destroying more innocent lives with its unlawful actions."

The commission concluded there was no evidence Canadian officials participated in or agreed to the decision to send Arar to Syria. But O'Connor recommended that in the future, information should never be provided to a foreign country where there is a credible risk that it will cause or contribute to the use of torture.

Most of the judge's 23 policy recommendations centered on the RCMP and emphasized the need to improve the force's internal policies for national security investigations and the sharing of information with other countries.

Arar's case has been regularly featured on the front pages of Canadian newspapers and public outcry led to the government calling an inquiry. Canada's federal government established the inquiry in 2004 to determine the role Canadian officials played.

O'Connor also found "troubling questions" about the role played by Canadian officials in the cases of three other Canadians of Arab descent -- Ahmad El Maati, Abdullah Almalki and Muayyed Nureddin. All claim they were tortured in Syria after traveling there on personal business, and all suspect that the RCMP, Canadian intelligence or both collaborated with their captors.

O'Connor said he could not get to the bottom of those cases because of the limited nature of his mandate. But he urged the government to appoint an independent investigator -- something short of a full-fledged public inquiry -- to look into those cases.

O'Connor sifted through thousands of pages of documents and sat through testimony from more than 40 witnesses. He delivered two versions of his report to the government: one classified, the other public. But portions of even the public edition of the long-awaited document were withheld due to security concerns.