BRUSSELS, Belgium – A lawyer for six Guantanamo Bay prisoners told a European Parliament committee yesterday that his clients were taken from Bosnia on an American plane that made stops in Turkey and elsewhere in Europe.

Stephen Oleksey also told the committee that Bosnian authorities cooperated in extraditing the Algerian terror suspects because they feared their country would lose American aid.

“The U.S. charge d’affaires told Bosnia that if these men are not arrested the U.S. would withhold its support to Bosnia,” Mr. Oleksey told the committee investigating allegations that American intelligence agents interrogated Al Qaeda suspects at clandestine prisons in Eastern Europe and transported some on secret flights that passed through Europe.

The six Algerians – including four with Bosnian citizenship – were arrested in October 2001 after American intelligence indicated they were planning attacks on American and British embassies in Sarajevo and an American military base in the northeastern city of Tuzla.

In a well-documented case, Bosnian authorities handed them over to American authorities in a secret late-night operation in 2002, just a few hours before the country’s human rights court was to order their release for lack of evidence. The six, who had worked in Bosnia for several years, all ended up in the American military detention center in Guantanamo Bay – on a flight that Mr. Oleksey said originated at the American Air Force’s Ramstein Air Base.

The arrest of the Algerians in 2001 was widely covered by the European press. America has not confirmed or denied Mr. Oleksey’s account.

Mr. Oleksey told the committee his information came from documents obtained under the American Freedom of Information Act and interviews with his clients, whom he has visited seven times at the detention center in Cuba.

“From that information you can discern the plane was on standby in Ramstein, flew to Tuzla, then to Turkey, took on additional detainees,” he said. “It was a grossly unlawful, wholly extralegal transfer.”

American authorities said the six included Bensayah Belkacem, suspected of serving as Osama bin Laden’s top lieutenant in Europe.

Belkacem was accused by America of making several phone calls to one of Mr. bin Laden’s aides – the operations chief of Al Qaeda in Afghanistan, Abu Zubaydah.

Bosnia’s highest court and the country’s top human rights panel both ordered the release of the men, saying the government lacked evidence that they were plotting post-September 11, 2001, attacks on American facilities in Bosnia.

Mr. Oleksey’s testimony supported earlier testimony by human rights activists who say America carried out secret flights from Europe to transfer terror suspects to detention centers abroad where they were tortured.

A draft of a preliminary report on the European Parliament committee’s findings was to be presented today.

Clandestine detention centers and secret flights via or from Europe to countries where suspects could face torture would breach the continent’s human rights treaties.