Members of the European Parliament have called on European governments to come clean about alleged secret CIA prison camps on their territory.
Prisoners held at secret prisons have been moved to Guantanamo
The calls followed an admission by the US president that the camps existed and were used to hold al-Qaeda suspects.
EU officials have been examining the allegations, but governments have until now denied that any prisons exist.
One MEP said it was vital to know whether any EU members or candidate countries had been involved.
"The location of these prison camps must be made public," said German MEP Wolfgang Kreissl-Doerfler in a statement.
"We need to know if there has been any complicity in illegal acts by governments of EU countries or states seeking EU membership."
Meanwhile US military prosecutors have said they hope to put key terrorism suspects held at the Guantanamo Bay detention centre - including 14 previously detained in the secret jails - on trial early next year.
Chief Pentagon prosecutor Col Maurice Davis said 75 suspects including Khalid Sheikh Mohammed, the alleged architect of the 11 September 2001 attacks, could appear before military tribunals. Some may face the death penalty.
The tribunals were stopped in June after the Supreme Court ruled that US President George W Bush did not have the authority to order them but left the way open for the president to seek Congressional approval for their resumption.
In a speech on Thursday charting his progress in improving US security since the 2001 attacks, Mr Bush called for swift action to get the suspects on trial.
"The sooner the Congress authorises the military commissions I have called for the sooner Khalid Sheikh Mohammed will receive the justice he deserves," he said.
'Part of the truth'
Council of Europe Secretary General Terry Davis said Mr Bush's admission of the existence of the secret jails was vindication for the Euro-MPs who have been investigating claims of clandestine CIA activity in Europe.
Until now, the US had admitted to picking up terrorism suspects in Europe, but had not confirmed having any secret prisons, or so-called "black sites".
In its interim report, the MEPs' committee said it was "highly implausible" that European governments were unaware of CIA activities on their territory.
Dick Marty, who investigated the issue of the CIA prisons for the Council of Europe, welcomed Mr Bush's disclosure.
"I'm pleased that finally, a bit late, the White House has acknowledged it.
"I hope that the American administration, which has started to tell a part of the truth, will say all the truth... I think it's even an obligation to their own citizens," the Swiss senator told the BBC.
In a TV address on Wednesday alongside families of victims of the 11 September 2001 attacks, Mr Bush described the prisons as a vital tool in the war on terror, saying that intelligence gathered had saved lives.
He said the CIA treated detainees humanely and did not use torture, adding that there were no longer any terrorist suspects being held as part of the programme.