Fourteen European nations colluded with U.S. intelligence in a "spider's web" of secret flights and detention centers that violated international human rights law, the head of an investigation into alleged CIA clandestine prisons said Wednesday.

Swiss senator Dick Marty said the nations aided the movement of 17 detainees who said they had been abducted by U.S. agents and secretly transferred to detention centers around the world.

Some said they were transferred to the U.S. detention center at Guantanamo Bay, Cuba, and others to alleged secret facilities in countries including Poland, Romania, Egypt and Jordan. Some said they were mistreated or tortured.

"I have chosen to adopt the metaphor of a global spider's web, a web that has been spun out incrementally over several years using tactics and techniques that had to be developed in response to new threats of war," Marty said.

Marty provided no direct evidence but charged that most European governments "did not seem particularly eager to establish" the facts.

"Even if proof, in the classical meaning of the term, is not as yet available, a number of coherent and converging elements indicate that such secret detention centers did indeed exist in Europe," he wrote, saying this warranted further investigation.

Marty relied mostly on flight logs provided by the European Union's air traffic agency, Eurocontrol, witness statements gathered from people who said they had been abducted by U.S. intelligence agents and judicial and parliamentary inquiries in various countries.

He concluded that several countries let the CIA abduct their residents, while others allowed the agency to use their airspace or turned a blind eye to questionable foreign intelligence activities on their territory.

He listed 14 European countries — Britain, Germany, Italy, Sweden, Bosnia, Macedonia, Turkey, Spain, Cyprus, Ireland, Greece, Portugal, Romania and Poland — as being complicit in "unlawful inter-state transfers" of people.

Some, including Sweden and Bosnia, already have admitted some involvement.

Marty put airports in Timisoara, Romania, and Szymany, Poland, in a "detainee transfer/drop-off point" category, together with eight airports outside Europe.

The 67-page report, addressed to the 46 Council of Europe member states, will likely be used by the human rights watchdog to put pressure on the countries implicated to investigate.

Marty said Romania and Poland were part of what he called a "renditions circuit."

He said one plane arrived in Timisoara, Romania, from Kabul, Afghanistan, on the night of Jan. 25, 2004, after having picked up Khaled El-Masri, a German who said he had been abducted by foreign intelligence agents in Skopje, Macedonia, and taken to the Afghan capital.

Marty said the plane with the crew that he said accompanied El-Masri stayed in Timisoara for 72 minutes before leaving for Spain.

"The most likely hypothesis of the purpose of this flight was to transport one or several detainees from Kabul to Romania," Marty said in the report, without elaborating.

Similarly, Marty said he believed the Szymany airport in northeastern Poland was used for a rendition flight in September 2003.

Officials in Romania and Poland denied the allegations Wednesday.

A parallel investigation by the European Parliament has said data show there have been more than 1,000 clandestine CIA flights stopping on European territory since the Sept. 11, 2001, attacks. Officials said it was not clear if or how many detainees were on board, and have not shed any light on allegations of CIA secret prisons.

Allegations that CIA agents shipped prisoners through European airports to secret detention centers, including compounds in eastern Europe, were first reported in November by The Washington Post.

Poland's prime minister denied Wednesday that CIA planes carrying terror suspects ever stopped or dropped off prisoners in Poland.

"This is slander and it's not based on any facts," Prime Minister Kazimierz Marcinkiewicz told reporters in Warsaw.

Former Polish President Aleksander Kwasniewski admitted he had heard of a few cases of secret landings by CIA planes in Poland, saying it was "natural" in the global fight against terrorism.

Romeo Raicu, head of Romania's parliamentary committee overseeing foreign intelligence services, told The Associated Press: "There is no evidence there were such detention bases in Romania."

He noted that agreements with the U.S. and NATO allow their aircraft to land in Romania and to fly over Romanian territory.

"The responsibility for what those planes transport is not Romania's responsibility," he said.

Britain said it had granted two of four U.S. rendition requests.

The first concerned Mohammed Rashid, a man later sentenced in the United States to seven years in prison in connection with the bombing of a Pan Am flight in 1982.

A second was to transport Mohamed Rashed Daoud al-Owhali via London's Gatwick airport. He was sentenced to life in 2001 for his role in the 1998 bombing of the U.S. Embassy in Nairobi.

"I have to say, the Council of Europe report has absolutely nothing new in it," British Prime Minister Tony Blair said.

Clandestine prisons and secret flights via or from Europe to countries where suspects could face torture would breach the continent's human rights treaties, including the European Convention on Human Rights.

The Council of Europe has no power to punish countries for breaching the treaty other than terminating their membership in the organization. Based on irrefutable evidence, the European Union might be able to suspend the voting rights of a country found to have breached the convention.