Poland has become the "political victim" of leaks years ago by U.S. officials who indicated the country hosted a secret CIA prison for terrorism suspects, the prime minister said Thursday.

Donald Tusk made the comments after a leading newspaper reported that Polish prosecutors have brought the first charges in the investigation they opened in 2008 into a now-closed CIA facility in the country.

"Let me remind you that really, in some sense, Poland is a political victim of indiscretions of some participants in the U.S. administration from a few years back," Tusk told a news conference, clearly referring to first word of it being mentioned in U.S. media.

Without confirming that a CIA site was ever based in Poland, Tusk said that the ongoing investigation is proof of Poland's democratic credentials and desire for greater transparency.

Poland will "no longer be a country where politicians _ even if they are working arm-in-arm with the world's greatest superpower _ could make some deal somewhere under the table and then it would never see daylight," Tusk said.

The Gazeta Wyborcza newspaper report Tuesday that charges were brought against a former intelligence head, Zbigniew Siemiatkowski, for exceeding his powers by depriving prisoners of war of their freedom and allowing corporal punishment.

Tusk said with the knowledge he has of the facts, he would not have brought the charges.

Siemiatkowski has refused to comment, telling The Associated Press he was bound by secrecy on the matter.

Former U.S. intelligence officials have identified Poland, Romania and Lithuania as nations that hosted some of the CIA's secret prisons.

Former CIA officials have told the AP the prison in Poland operated from December 2002 until the fall of 2003, and that prisoners were subjected to harsh interrogations. The Council of Europe and the United Nations have also said they have evidence the site existed.

Two prisoners at Guantanamo Bay, Abd al Rahim al-Nashiri and alleged al-Qaida facilitator Abu Zubaydah, have been given victim status in the investigation in Poland after claiming they were held in the country and subjected to harsh treatment.

Politicians in Poland have vehemently denied the claims, particularly Aleksander Kwasniewski and Leszek Miller, who were the president and the prime minister at the time the CIA ran the prison.

Poland backed the U.S. as it pursued the so-called "war on terror" after the Sept. 11, 2001, terror attacks.