WASHINGTON - Maher Arar's bid to hold U.S. officials legally accountable for his year-long ordeal in a Syrian prison reached a dead end Monday when the U.S. Supreme Court summarily rejected his final appeal.

Arar, a Syrian-born Canadian citizen who in 2002 learned first-hand about controversial American rendition practices, had been seeking the right to sue a number of top U.S. officials, including former attorney general John Ashcroft.

As is standard practice, the court offered no explanation for its decision, which Arar had to admit marked the end of his last line of legal recourse in the U.S.

The decision "eliminates my last bit of hope in the judicial system of the United States," he acknowledged in a statement.

"When it comes to 'national security' matters, the judicial system has willingly abandoned its sacred role of ensuring that no one is above the law.... Unless the American people stand up for justice they will soon see their hard-won civil liberties taken away from them as well."

Arar, a Syrian-born Canadian citizen, was detained in New York by U.S. immigration agents on Sept. 26, 2002.

In accordance with a policy allowing officials to deport suspected terrorists to foreign countries, U.S. immigration agents determined that he could be legally sent to Canada, Syria or Switzerland.

He was eventually deported to Syria. From the grave-like cell where he was held and tortured for nearly a year, Arar gave made-up confessions to Syrian military intelligence officers about supposed involvement with Osama bin Laden's al-Qaida network.

"It's a huge disappointment for all of us, really," said Maria LaHood of the New York-based Center for Constitutional Rights.

"We've been working on the case for six years, for Maher it's been eight years since it happened, and he's been seeking justice steadfastly ever since. This is the end of the line for the U.S. courts, unfortunately."

A federal commission of inquiry led by Justice Dennis O'Connor later concluded that erroneous information the RCMP passed to U.S. authorities very likely led to the Ottawa telecommunication engineer's ordeal.

O'Connor also found Canadian officials intentionally leaked inaccurate details about Arar to the media in an effort to damage his reputation and protect their own.

Arar eventually received an apology and $10.5 million in compensation from the federal government. LaHood said she believes the U.S. government should follow suit by acknowledging its own complicity in the affair.

"The United States has got to admit its mistakes. It's got to acknowledge the wrongdoing that it's done. It's not only about clearing Maher's name and getting justice for him, it's about making sure that torture doesn't happen in the United States."

In his U.S. court case, Arar alleged high-ranking U.S. officials conspired with Syrian authorities to have him tortured.

Lower courts dismissed the case on the grounds that it raised national security concerns, LaHood said, adding the responsibility for a remedy was left with the political branches.

Arar's legal team will focus its efforts on persuading Congress and even U.S. President Barack Obama to issue a formal apology, she said.

Arar may also have international options available as well, LaHood noted -- the RCMP has launched a criminal investigation into the role played by both Syrian and U.S. officials.

With files from The Associated Press