Poland's inquiry began in 2008, and the deadline has already been postponed once, with the completion date being put back to February this year.
Now it has transpired that the results may not see the light of day until this August.
“We would like to complete our inquiry this year,” Warsaw Prosecutor Waldemar Tyl told the national broadcaster TVP.
“We are also preparing a request for legal assistance from the USA,” he added.
The USA has previously refused to cooperate in the enquiry.
Law suits have been taken out against Poland by al-Qaeda suspects who claim they were held, and tortured, illegally in the north east of the country..
The trial resumed this month of one such prisoner, Abd al Rahim al Nashiri, currently being held in Guantánamo Bay, who is being charged with being responsible for the attack on the USS Cole in Yemen which killed 17 sailors.
His lawyer Richard Kammen asked the military judge to leave the prisoner unshackled when he meets with attorneys. The shackles recall his conditions when agents put a gun to his head and threatened him with a power drill, said the lawyer.
In October 2011, Thomas Hammarberg, the Council of Europe's Commissioner for Human Rights said that, “it is clear that Poland hosted secret CIA prisons between December 2002 and September 2003. We know who was held there and what interrogation methods were used. They can be described as torture.
Both Leszek Miller, the prime minister during the time that the alleged ‘black site’ prison was operative, and the n then president Aleksander Kwasniewski have denied any knowledge of the CIA prison.
Last May, after a rash of headlines on the affair in the Polish press, Miller said that “writing about CIA prisons in Poland is an invitation for al-Qaeda. Euro 2012 is a wonderful occasion for it [al-Qaeda] to remind itself of Poland”.
Current president Bronislaw Komorowski has said that “he wants to finally get to the bottom of the question of the existence of CIA prisons in Poland.” (pg/nh)
source: IAR/PAP