Drawn up by Swiss parliamentarian Dick Marty the report names 14 European countries that colluded in or tolerated the transfers of suspects and says that two of them, Poland and Romania, may have even harboured the secret CIA detention centres.
Although it did not openly accuse Poland and Romania of housing the prisons, the report said that there was "a preponderance of indications" that secret detention centres were operated near aircraft landing points.
"It is now clear -- although we are still far from establishing the whole truth -- that authorities in several European countries actively participated with the CIA in these unlawful activities. Other countries ignored them knowingly, or did not want to know," the report said.
Bosnia-Hercegovina, Britain, Italy, Macedonia, Germany, Sweden and Turkey were all said in the report to have been "responsible, at varying degrees... for violations of the rights of specific persons".
While Cyprus, Greece, Ireland, Poland, Portugal, Romania and Spain "could be held responsible for collusion, active or passive." It blamed the United States for creating "this reprehensible network".
Poland and Romania led European countries in rejecting the report. In Warsaw, Prime Minister Kazimierz Marcinkiewicz dismissed the allegations as "libel" with "no basis in fact," according to Poland's PAP news agency.
Poland has denied housing the secret CIA prisons since the allegations first surfaced in November, but the country’s ex-president Aleksander Kwasniewski had said shortly before he left office in December that CIA aircraft could have made stopovers in the country. He strongly denied the US ran secret prisons in his country.
“Pure speculation”
Romanian government officials said that the accusations were "pure speculation" and slammed as unacceptable the "accusations based on 'indications'."
"Mr Marty's report does not provide any proof of the presence of detention centres in Romania," Norica Nicolai, president of the parliamentary commission investigating alleged CIA flights to Romania, told news agency AFP.
"There is no proof that the planes which landed in Romania belong to the CIA, or of any CIA prisons in this country," she added.
But Belgium urged Poland and Romania to lay their cards on the table and clear up the murky situation, "There are serious indications which show that strange things have happened. Romania and Poland must clear this up -- that is the priority now," Belgian Foreign Minister Karel De Gucht said.
Greek officials did not deny that the CIA flights had transited via the country, but said it had not breached international aviation laws. "Greece strictly abides by the laws, rules and international treaties on civil aviation for every aircraft arriving in or leaving the country," government spokesman Evangelos Antonaros told reporters.
“Nothing new”
A spokesman for the German government, Thomas Steg, said Berlin would not comment on the allegations, so as not to impede the work of the country’s judiciary, which is hearing several cases cited in Mr Marty’s report.
Spain "categorically" rejected the accusations, with an unnamed government spokesman in Madrid saying, "Spain has in no way, either actively or passively, taken part in operations to transfer prisoners".
British Prime Minister Tony Blair dismissed the document as containing "absolutely nothing new" - echoing a comment made by the Foreign Office.
The United States criticised the report, saying it is heavy on charges but thin on facts, "This would appear to be a rehash of the previous efforts by this group. I don't see any new solid facts in it. There seem to be a lot of allegations but no real facts behind it." State Department Spokesman Sean McCormack told a press briefing.
Mr McCormack decried the "tone in the report and some of the discussion that there's something inherently bad or illegal about intelligence activities." He defended the practice saying that renditions "are an internationally recognized legal practice. Carlos the Jackal wouldn't be in jail today without the practice of rendition."
The Venezuelan-born Carlos, whose real name is Illich Ramirez Sanchez, was convicted of terrorism and is serving a life sentence in a French jail. He was captured in Sudan, in 1994, and hauled in a sack to Paris by French secret service agents. Venezuela questions whether his rights were violated when he was abducted and whisked away to France.
White House press secretary Tony Snow would not comment on the report, but said that the United States does not condone or practice torture, "Furthermore, we will not agree to send anybody to a nation or place that practices torture."
The Council of Europe, which is a separate body from the European Union, was set up after World War II to promote democracy and human rights across the continent. All 25 EU countries are part of the 46-member organisation.
Foreign Ministers from the European Union are expected to discuss the Council’s report on Monday in meeting in Luxembourg.