A leading Homeland Security Department investigator said Thursday his office is re-examining the conclusions of a probe that exonerated the government in the case of a Canadian engineer who was seized by U.S. officials, sent to Syria and allegedly tortured.

The chief of internal investigations at the Homeland Security, Richard Skinner, said at a congressional hearing that his office could not rule out that the United States wanted to send Maher Arar to Syria because it believed he would be tortured. He said that the U.S. Justice Department had been informed of that possibility and is currently investigating.

Skinner said that his office has new information that contradicts an earlier conclusion of its own investigation on the Arar case.

Skinner was releasing an unclassified, redacted version of its report after testifying at a hearing Thursday on the Arar investigation. The hearing was held by two subcommittees of the House of Representatives' Judiciary and Foreign Affairs Committees.

Arar's case involves one of the most publicly scrutinized incidents of extraordinary rendition, a practice in which the U.S. government sends foreign terror suspects to third countries for interrogation.

Lawmakers at the hearing criticized the Bush administration for taking so long to release details on Arar's case and for keeping much of the report classified.

Democratic Rep. Bill Delahunt, chairman of the House Foreign Affairs' subcommittee on International Organizations, Human Rights, and Oversight, called on the two committees to ask the Justice Department to appoint a special prosecutor to investigate whether the administration broke U.S. laws on torture.

Skinner's investigation, which was requested by the chairman of the House Judiciary Committee, Democratic Rep. John Conyers, found that U.S. immigration officials acted appropriately in determining that Arar could be expelled from the United States.

Arar, a Syrian-born Canadian citizen, was detained by U.S. immigration agents on Sept. 26, 2002, as he stopped over in New York's John F. Kennedy International Airport on a flight from Switzerland en route home from a vacation. Days later, he was sent by private jet to Syria where, according to Canadian officials, he was tortured.

After nearly a year in a Syrian prison, he was released without charges and returned to Canada.

U.S. immigration officials determined that Arar could be legally deported to Canada, Syria or Switzerland. Skinner said that Switzerland was ruled out for reasons that are classified. In written testimony, he said that Arar requested to be returned to Canada, but the Justice Department determined that doing so would be "prejudicial to the interest of the United States."

Skinner's testimony said that officials "concluded that Arar was entitled to protection from torture and that returning him to Syria would more likely than not result in his torture."

U.S. officials received assurances from Syria that Arar would not be tortured, but Skinner said, those assurances were ambiguous.

The Canadian government has apologized to Arar and agreed to pay him almost $10 million in compensation. Some U.S. lawmakers, including many at Thursday's hearing, also apologized to Arar last year.

The administration has not apologized and has refused to say much about its extraordinary rendition program other than it is an extremely important tool in combating terrorists.

A lengthy Canadian investigation into the Arar case found the Royal Canadian Mounted Police wrongly labeled him an Islamic fundamentalist and passed misleading and inaccurate information to U.S. authorities, which very likely led to Arar's arrest and deportation.

The inquiry also determined Arar was indeed tortured, and it cleared him of any terror links or suspicions.

Legal experts say the case shows the United States has violated a 1998 law that specifically prohibits the government from turning a suspect over to a foreign country where the suspect might be tortured. U.S. authorities say they do not turn over suspects to other countries without diplomatic assurances that they will not be tortured.