Revealed: US refused to aid Polish probe of CIA black site detailed by Raw Story in '07

A secret terrorism "black site" prison in Poland, confirmed to exist in , was the subject of an international dispute between US and Polish authorities, an official document released Tuesday revealed.

Poland's request for US cooperation in a probe of the secret CIA prison was declined, according to a letter released by the Helsinki Foundation, a human rights organization located in Warsaw, Poland.

Intelligence officials who spoke to Raw Story on the condition of anonymity identified the site as a component of a Polish intelligence training school outside the northern Polish village of Stare Kiejkuty. While previously suspected, the facility had never been conclusively identified as being part of the CIA's secret rendition and detention program.

Only the Polish prime minister and top Polish intelligence brass were told of the plan, in which US agents quietly shuttled detainees from other holding facilities around the globe for stopovers and short-term interrogation in Poland between late 2002 and 2004.

According to a confidential British intelligence memo shown to Raw Story, former UK Prime Minister Tony Blair told Poland's then-Prime Minister Leszek Miller to keep the information secret, even from his own government.

"US authorities said that they considered the matter closed," the prosecutor's letter claimed.

The complex at Stare Kiejkuty, a Soviet-era compound once used by German intelligence in World War II, is best known as having been the only Russian intelligence training school to operate outside the Soviet Union. Its prominence in the Soviet era suggests that it may have been the facility first identified -- but never named -- when The Washington Post's Dana Priest revealed the existence of the CIA's secret prison network in November 2005.

Polish prosecutors launched an investigation in August 2008 into the allegations. They made their request for US legal cooperation in March 2009, the letter showed.

The Polish government has officially rejected claims that it ever ran a secret CIA prison.

However, Polish campaigners said in July that they had obtained official records about seven CIA planes -- five of them carrying passengers -- which landed in 2002 and 2003 at Szymany, a Polish military base in northeast Poland. Alleged to have been among the detainees was Khaled Sheikh Mohammed, charged with masterminding the September 11, 2001 attacks in the United States.

In a key legal step this October, another alleged detainee, Abd al-Rahim al-Nashiri, was granted the formal status of "victim" by Polish prosecutors.

Al-Nashiri, suspected by Washington of plotting the October 2000 attack on the USS Cole in Yemen that killed 17 sailors, is currently being held at the US military base at Guantanamo Bay, Cuba, since September. Two weeks ago, lawyers for another Guantanamo inmate, Abu Zubaydah, asked for his case to be folded into the Polish probe.

With AFP and prior reporting by Larisa Alexandrovna and David Dastych.