WASHINGTON (Reuters) - The U.S. Justice Department is investigating whether agency attorneys improperly deported Canadian Maher Arar to his native Syria, where he says he was tortured after he was detained at a U.S. airport due to his erroneous placement on a terrorist watch list.

Maher Arar listens to a question during a news conference in Ottawa January 26, 2007. REUTERS/Chris Wattie

Justice Department spokesman Peter Carr said on Friday the investigation by its Office of Professional Responsibility began last year, following a report by the Department of Homeland Security’s inspector general into the matter.

Arar’s case has become a sore spot in U.S.-Canada relations.

Declassified portions of the report were not released until this week. It found that U.S. authorities ignored Arar’s fears of torture if he were sent to Syria.

It said immigration and Justice Department officials disregarded normal procedure, which would have been to send Arar back to Canada or to Switzerland, where his flight originated.

In addition, it found, the Immigration and Naturalization Service had concluded that Arar was entitled to protection from torture under international law and that “returning him to Syria would more likely than not result in torture.”

Yet it received only ambiguous assurances that he would be protected, and deported him anyway, the report said.

Homeland Security Inspector General Richard Skinner told Congress on Thursday that he was reopening his investigation into the incident and that Justice Department officials and attorneys may have acted illegally.

He said he could not rule out that the United States sent Arar to Syria because it wanted him interrogated under conditions that would violate U.S. law.

Arar was seized in late September 2002 by immigration officials at New York’s Kennedy Airport while en route to Canada from a family visit to Tunisia. He was sent to Jordan the next month, was taken into custody by Syrian officials, and released a year later saying he had been tortured.

The Canadian government has cleared Arar of any links to terrorist groups and apologized and paid him millions of dollars in compensation. It said the Royal Canadian Mounted Police had wrongly told U.S. border agents that Arar was suspected of being an extremist.

U.S. Secretary of State Condoleezza Rice last year acknowledged the United States had mishandled the case, but she stopped short of an apology. “We do absolutely not wish to transfer anyone to any place in which they might be tortured,” Rice said at the time.