Terror suspect al-Nashiri: wikipedia
In some of the most detailed allegations yet to be made on the existence of the secret prison in Poland, the newspaper reports that former CIA officials have told them that some of the money was used to improve security at a villa three-hours drive from Warsaw, where terrorist suspects Abd al-Rahim al-Nashiri and Abu Zubaida were already being held.
The so-called 'black site' - code named “Quartz” by the CIA - was a two-story villa in Stare Kiejkuty in the north-eastern lake district, used by Polish intelligence services as a training facility, which was handed over to the American agents after sites in Thailand and Cambodia proved unsuitable.
A barn at the back of the villa was also converted into a cell.
The facility "was pretty spartan,” an unnamed CIA official has told the Washington Post.
At the villa, the terrorist suspects, after agreement from the US Justice Department, were then subjected to "enhanced interrogation techniques" which included "slapping, sleep deprivation and waterboarding," the newspaper reports.
Nashiri was also blindfolded and tortured by "mock execution" where a drill was put to his head, according to several former CIA officials.
The site was closed down in September 2003, with around 11 detainees held by that time being sent to Romania, Morocco and Lithuania.
In December, Abd al-Rahim al-Nashiri and Abu Zubaida - who are still being held by the US at the infamous Guantanamo Bay site - took their case to the European Court of Human Rights, where lawyers alleged that Poland had violated international law by allowing them to be incarcerated and tortured.
Poland's left wing prime minister in 2002 and 2003, Leszek Miller, has long denied any knowledge of the CIA 'black site'.
A Polish investigation, set up following the election of the Civic Platform government in 2007, has yet to report its findings, saying that the probe was being hampered by US officials refusing to take part.
American and Polish officials in the US refused to comment on the allegations made by the Washington Post.
Polish foreign minister Radoslaw Sikorski said on Friday morning that questions as to whether there was a CIA prison in Poland "should be addressed to Leszek Miller".
Miller again dismissed the allegations, telling the Superstacja television station: "[The report] sounds like a Hollywood movie". (pg)
This article was updated with quotes from Miller and Sikorski at 10.50 am