Jordanian terror suspect Abu Qatada was on Saturday sent back to prison by a British judge, just two days before the government was due to make a fresh bid to deport him.
The radical cleric, who has been dubbed Osama bin Laden's right-hand man in Europe, was found to have breached the conditions of his bail granted last November.
"The appellant's bail is revoked forthwith, and he is ordered to be detained," judge Stephen Irwin said in an order, adding that Abu Qatada would be detained at the high-security Belmarsh prison in southeast London.
Abu Qatada, 52, had been rearrested at his home in north London by officials from the UK Border Agency on Friday.
His case was then assessed in an urgent telephone hearing on Saturday before a judge of the Special Immigration Appeals Commission (SIAC).
The judge said there was "strong prima facie evidence" that Abu Qatada had breached a bail condition that banned him from having mobile phones switched on in his house while he was there.
It also bans digital media devices, re-writable CDs or pen drives from being brought into his house.
Another bail hearing will be held on March 21, the judge said.
A spokesman for Britain's Judicial Office said that the hearing would give "both sides the opportunity to submit more evidence in the matter."
The Home Office, or interior ministry, said it was "pleased" about the decision to revoke Abu Qatada's bail for "serious" breaches of his bail conditions.
"We will vigorously argue our case at the next hearing on March 21," the Home Office spokesman said.
Successive British governments have been trying for a decade to deport Abu Qatada, whose real name is Omar Mohammed Othman, to Jordan.
Abu Qatada was convicted in absentia in Jordan of involvement in terror attacks in 1998.
Lawyers for Home Secretary Theresa May will on Monday challenge a ruling by the SIAC that Abu Qatada cannot be deported over fears that evidence obtained through torture could be used against him in any retrial.
The cleric was released on bail following November's ruling, causing huge frustration in London.
Under the terms of his release last year, Abu Qatada was placed under a curfew and only allowed to leave his home between 8:00am and 4:00pm.
He also had to wear an electronic tag, and restrictions were placed on who he could meet.
The Sun newspaper published photographs of Abu Qatada being led away by officials on Friday, under the headline "Nabu". He was wearing black clothes and a white prayer cap with a jacket covering his hands.
It also reported that his London home had been raided by police on Thursday.
Scotland Yard confirmed that counterterrorism officers had on Saturday completed searches at four addresses in the British capital but found no hazardous materials.
There had been no further arrests in connection with the searches, police said.
Abu Qatada arrived in Britain in 1993 claiming asylum and has been a thorn in the side of successive British governments.
A Spanish judge once branded him the right-hand man in Europe of bin Laden, although Abu Qatada denies ever having met the late Al-Qaeda leader.
Prime Minister David Cameron voiced his frustration after the cleric's release in November, saying he was "completely fed up with the fact that this man is still at large in our country".
Britain initially detained Abu Qatada in 2002 under anti-terror laws imposed in the wake of 9/11 but he was released under house arrest.
A decade of court battles followed to first keep him behind bars and then remove him from Britain.
The European Court of Human Rights ruled last year that he could not be deported while there was a "real risk that evidence obtained by torture will be used against him" in any retrial.
The home secretary ordered his extradition anyway after Jordan gave assurances that he would be treated fairly.
But SIAC, a semi-secret panel of British judges that deals with national security matters, blocked the move and he was freed on bail.
May will contest this ruling on Monday at the Court of Appeal.