CIA 'secret prison' found in Romania - media reports
The CIA operated a secret prison in the Romanian capital Bucharest where terrorism suspects were interrogated, an investigation by the Associated Press and German media has found.
Former CIA operatives identified the building where, they said, detainees were held and tortured.
The building belongs to a Romanian agency, Orniss, which stores classified information from the EU and Nato.
Orniss has denied hosting a CIA prison and the CIA has refused to comment.
The investigation, by the Sueddeutsche Zeitung newspaper and the German TV network ARD, said those held in the secret prison included Khaled Sheikh Mohammed, who has admitted organising the 9/11 attacks.
He was seized in Pakistan in March 2003 under the US programme known as "extraordinary rendition" - the extra-judicial detention and transfer of terrorism suspects.
He has been in the US detention centre at Guantanamo Bay since 2006, where he is awaiting trial.'Bright Light'
The building identified in the German investigation houses the Office of the National Register for Secret State Information, or Orniss.
Orniss has denied all claims that its premises were used as a CIA prison.
Asked whether the building was ever used to hold Islamist terrorism suspects, Orniss deputy head Adrian Camarasan told the Sueddeutsche: "Here? No!"
The building, at 4 Mures Street, was codenamed "Bright Light", the Sueddeutsche reported.
The controversy over secret prisons is one of the most controversial legacies of the "war on terror." Not just the location but the very existence of the so-called CIA "black sites" was kept secret for many years after 9/11.
Top al-Qaeda figures such as Khalid Sheikh Mohammed and Abu Zubaydah simply disappeared. Intelligence reports began to seep back to some of America's allies from their interrogation but no-one was sure where they were being held - or how they were being treated.
Once it became public in 2005/6 that the CIA had operated a secret prison network and that it had engaged in controversial practices like waterboarding, investigators and journalists used flight records to try to work out where the prisons might be located.
They used this and other evidence to assert the prisons may have been located in Lithuania, Thailand, Romania and Poland among other countries. The accusations have usually been denied but have still led to awkward questions for the "host" countries in terms of who might have known what.
One former CIA operative who said he visited the site frequently was quoted as saying: "It was very discreet there. It was not as though Romanian officials came out to greet me."
Allegations of a network of CIA "black sites" in countries including Romania first surfaced in 2005 but were denied by Washington.
In 2007, an investigation by the Council of Europe accused Romania of operating a secret prison - accusations denied by Bucharest. The CIA called the report "biased and distorted" and said it had operated legally.
Council of Europe investigator Dick Marty on Thursday welcomed the new report.
"The dynamic of truth has run its course and we are at last beginning to learn what really happened in Bucharest," he said in a statement.
However, he criticised the lack of what he called a "serious judicial inquiry" in Romania.
In 2006, then-US President George W Bush admitted that terror suspects had been held in CIA-run prisons overseas, but he did not say where the prisons were located.
A BBC investigation in 2010 alleged the CIA used a secret Polish prison where Khaled Sheikh Mohammed was subjected to simulated drowning - the practice known as waterboarding.
The Associated Press news agency, which worked with the Sueddeutsche and ARD on their investigation, says the alleged prison in Romania opened in 2003 after the CIA decided to empty the black site in Poland.
It quoted former US officials speaking on condition of anonymity.
The basement consisted of six prefabricated cells, each with a clock and arrow pointing to Mecca, the officials told AP.
Waterboarding was not used in Romania, they said.
Other detainees of intelligence value to the US held in Romania included Ramzi Binalshibh and Abu Faraj al-Libi, AP reported.
The Romanian foreign minister told the Council of Europe at the time of its investigation: "No such activities took place on Romanian territory."
The ARD programme will be broadcast at 22:00 local time (21:00 GMT) on Thursday.