Radical Muslim cleric Abu Qatada has been arrested in London for breaching his bail terms, days before the British government begins an appeal against a court decision blocking his deportation to Jordan.
Accused by the British authorities of posing a security risk and being a spiritual inspiration for one of the 9/11 hijackers, Qatada is wanted in his native Jordan to face terrorism charges.
Successive British governments have tried for years to get rid of the cleric, who has been in and out of jail since first being arrested in 2001 and is on bail under tight restrictions including a 16-hour curfew.
In the latest of a series of legal blocks to his deportation, the Special Immigration Appeals Commission (Siac) ruled in his favor in November last year. Qatada says a trial in Jordan might be skewed by evidence obtained using torture.
"The UK Border Agency arrested a 52-year-old man from north London for alleged breaches of his bail conditions imposed by the Special Immigration Appeals Commission," a spokesman for the Home Office, or interior ministry, said on Saturday.
In line with the usual practice of the British authorities, the spokesman declined to confirm the man was Abu Qatada, but did not deny media reports identifying the cleric.
The spokesman said the arrest took place on Friday and that the breach of bail terms would be considered by Siac at the earliest opportunity.
Qatada's successful appeal to Siac in November was a setback for Home Secretary Theresa May, who has denounced the repeated legal obstacles to his deportation.
The government's appeal against the Siac decision is scheduled to be heard in the Court of Appeal on Monday. It was not clear whether there was any connection between Qatada's arrest and the looming appeal.
The Sun newspaper, which first reported news of Qatada's arrest, said counter-terrorism police had searched his north London home for 12 hours on Thursday.
London police declined to confirm the report of the search, saying only that officers had searched three residential addresses and one business address in the capital on Thursday.
A spokesman said the searches were "in connection with ongoing inquiries by the counter-terrorism command", adding that no hazardous materials had been recovered.
The cleric, a Jordanian of Palestinian origin, was once described by a Spanish judge as "Osama bin Laden's right-hand man in Europe".
Britain says videos of his sermons influenced Mohammed Atta, ringleader of the September 11 attacks on New York and Washington in 2001.
Under a deal struck in 2005, Jordan has given Britain diplomatic assurances about his treatment and guarantees that court hearings would be fair.
Jordan convicted Qatada in his absence of encouraging militants there who planned bomb attacks in 1999 and 2000. Under the 2005 deal, however, he will have a retrial if he is eventually returned to Jordan.