By Adam Easton
BBC News, Warsaw
Szymany airport is said to be where CIA interrogations took place
Polish intelligence sources have for the first time confirmed that the US Central Intelligence Agency (CIA) ran a secret prison facility on Polish soil.
The admission comes after a report found the CIA had operated prisons for terror suspects in Poland and Romania.
Polish and Romanian officials denied the claims, but last month Warsaw launched a new inquiry into the matter.
In 2006, US President George W Bush admitted the CIA had held suspects in secret jails but he did not say where.
Two anonymous intelligence officers made the claims about facilities being located in Poland in the daily Dziennik.
One of them states that between 2002 and 2005 the CIA held terror suspects inside a military intelligence training base in Stare Kiejkuty in north-eastern Poland.
The officer says only the CIA had access to the isolated zone, which was used because it was a secure site far from major towns and was close to a former military airport.
Both the then Prime Minister, Leszek Miller, and President, Aleksander Kwasniewski, knew about the base, the newspaper reports.
However the officer says it was unlikely either man knew if the prisoners were being tortured because the Poles had no control over the Americans' activities.
Both leaders have always denied the existence of any such base.
Last year a Council of Europe report quoted unnamed CIA sources as saying that "high-value detainees", including Khalid Sheik Mohammed - the alleged mastermind of the 9/11 attacks on the US in 2001 - had been interrogated in Poland.
The current Polish government says it has no knowledge of the base but it has sanctioned a new investigation into the claims.