The CIA held terror suspects inside a military intelligence training base in Stare Kiejkuty, north-eastern Poland from 2002 to 2005, anonymous Polish intelligence officers have said.
Public prosecutor Jerzy Mierzewski had wanted to charge officials from the 2001-2005 Democratic Left Alliance government with violating the constitution, unlawful detention and participation in crimes against humanity, the daily reported.
The left-wing party is today Poland's second largest opposition party. Polish politicians who were in power when the prisons allegedly operated have denied allegations that CIA prisons were located in the country.
Mierzewski, however, was withdrawn from the case two weeks ago, the daily wrote. His supervisor, Dariusz Korneluk, declined to comment on the reason for the dismissal.
Mierzewski had asked international law experts in February to determine whether the CIA prisons were lawful and constitutional, the daily said.
No US assistance
The law experts replied in May in a 50-page report that the prisons were unlawful, according to both international law and the Polish constitution. The US regulations that allow for waterboarding were also against international law, the experts added.
Prosecutors have been investigating allegations about the secret prisons since 2008, but have not released their findings.
According to Wyborcza, Poland and the US agreed that the US would not reply to a Polish request for assistance in the case. This would prolong the investigation until the case could be suspended, the daily reported, citing a source in the prosecutor's office.
Prosecutors representing Saudi national Adb al-Rahim al-Nashiri, accused in the bombing of the USS Cole in 2000, claim the man was tortured at the facility between 2002 to 2003. Al-Nashiri was subjected to waterboarding and mock executions with a power drill while he was naked and hooded, the prosecutors said.
Flight logs obtained from Polish officials in February 2010 confirmed that CIA aircraft landed in Poland during 2003. Human rights groups suspect these were rendition-related flights.
The logs, which were obtained by human rights organisations, showed that CIA-chartered aircraft landed in Szymany, north-eastern Poland, at least six times in 2003.
New York-based Human Rights Watch claimed in a 2005 report that secret CIA prisons in Poland were used to house suspected terrorists from Afghanistan.