VILNIUS (Reuters) - Lithuania must properly investigate allegations it hosted a secret CIA prison for al Qaeda and, if true, take responsibility for its actions, the president said on Tuesday.

U.S. ABC news reported in August that Lithuania was the third European country after Poland and Romania to have provided the CIA with facilities for detaining, and possibly interrogating, suspects.

President Dalia Grybauskaite, who is in charge of foreign and defense policy and tends to be outspoken, said an investigation by parliament, which found no jail, had been only a formality.

“It (the investigation) raises the question of political will ...,” she told a news conference ahead of a meeting with Council of Europe Human Rights Commissioner Thomas Hammarberg.

“The West is waiting for answers from us and will look at us with suspicion as long as Lithuania cannot clear away the shadows which hang above Lithuania or, if it is confirmed, to take responsibility and to apologize to the international community for human rights (abuses).”

She said she had suspicions the jail did exist and that the international community thought this too, without giving details why.

She also said a request had been sent to the United States for cooperation in a probe. Hammarberg said he was convinced the truth would come out. “I think this is a serious matter that needs to be clarified,” he told journalists.

ABC News has said a secret CIA prison operated near Vilnius airport from early 2004 to late 2005 and that CIA planes flew into Lithuania with top level al Qaeda suspects.

The Washington Post reported for the first time in 2005, quoting unnamed CIA sources, that CIA prisons existed in Europe as part of former President George W. Bush’s “war on terror” in the wake of the September 11, 2001, attacks.