Jordan-born radical preacher Abu Qatada, once dubbed “Europe's Osama bin Laden” and still regarded by Britain as a threat to national security, was on Monday released from a high-security prison after a judge ruled that his continued detention without trial was illegal.

This followed a verdict by the European Court of Human Rights blocking Britain's bid to deport him to Jordan, where he faces prosecution on charges of terrorism.

The court upheld his claim that if deported he was likely to be tried on the basis of evidence obtained under torture.

Mr. Qatada, who spent six-and-a-half years in jail, was released on strict bail conditions including a 22-hour curfew allowing him to leave home for a maximum of an hour twice a day. He will be electronically tagged and banned from using a mobile phone or the internet. He will also not be allowed to attend a mosque, lead prayers or publish any statement.

But the restrictions could be lifted if within three months the government is not able to show “demonstrable progress” in its talks with Jordan on his deportation, said the judge.

The government said it was “committed” to removing Mr. Qatada from the country and hoped to resolve the issue soon.

“We will take all measures necessary to protect the public. We are committed to removing him from the country. We want to see him deported,” said a Downing Street spokesman.

Under an existing agreement, Jordan has assured Britain that Mr. Qatada would not be tortured, but the European court ruled that this did not rule out the possibility of torture-tainted evidence being used against him.

Mr. Qatada, whose real name is Omar Othman, fled to Britain in 1993 claiming that he was tortured by Jordanian authorities. He was convicted in absentia for his alleged involvement in two major terrorism plots in Jordan.