"It's a great day for justice and a sad day for arrogance and oppression

Mazen al-Najjar

His release came after US Attorney-General Janet Reno lifted a legal stay on his release, ordered last week by the Federal Board of Immigration Appeals.

According to the US Government, Mr Najjar had links to Middle East terrorists and was a threat to national security.

Secret evidence

He was held under a legal provision that allows secret government evidence to weigh against a suspect, but has never been charged with a crime.

We are absolutely ecstatic Janet Reno has come to her senses and stopped this unconstitutional detention

Martin Schwarz Mazen al-Najjar's lawyer

Mr Najjar, a 43-year-old academic, has denied any involvement in terrorism all along.

"I hope this is the end of the nightmare," said Mr Najjar, speaking to reporters immediately after his release.

"We are absolutely ecstatic Janet Reno has come to her senses and stopped this unconstitutional detention," said Mr Najjar's lawyer Martin Schwartz.

Despite his release, an accompanying statement from Mrs Reno said that Justice Department officials "anticipate he could be deported from the United States soon".

Release delays

Immigration Judge Kevin McHugh had ordered Mr Najjar's release two weeks ago, saying the government failed to provide Mr Najjar with enough information to defend himself.

Friends and relatives cheered Najjar's release

However, his release was delayed several times, most recently on Tuesday when Mrs Reno intervened saying she wanted more time to review the case.

The US allegations were based on Mr Najjar's links with two American Islamic groups - the Islamic Committee for Palestine and the World and Islam Studies Enterprise.

The World and Islam Studies Enterprise is a think-tank affiliated with the University of South Florida, while the Islam Studies Enterprise describes itself as aiming to promote understanding of Muslim issues in the US.

But the US government argues the groups were fronts for fund raising for Islamic Jihad militants.