In its most detailed report yet on alleged secret rendition flights of terror suspects, Amnesty International said recent interviews with former detainees have lent support to the idea that eastern European countries may have been involved in secret CIA flights to so-called "black site" prisons.

The experiences of three Yemeni men held in the secret prisons are at the center of the report released Wednesday.

The report includes testimonies in February and March from Muhammad Bashmilah, Muhammad al-Assad and Salah Nasser Salim Ali, also known as Salah Qaru — men who Amnesty says are the first black-site prisoners to speak publicly after their release.

Bashmilah said he was detained in Jordan in October 2003 while on a trip to visit his mother and then he was flown to Afghanistan. Ali said he was detained in Indonesia in August 2003 and then flown to Jordan, where he was taken into custody and then flown to Afghanistan. Al-Assad said he was detained in Tanzania in 2003 and flown to Djibouti and then allegedly Afghanistan, according to an Amnesty source in Tanzania. Amnesty declined to provide details about the source.

From Afghanistan, the three men described travel times, climate, temperature, sunrises and prayer times that changed according to daylight savings time in detailed descriptions Amnesty says indicates they could have been held in eastern Europe.

The men were held for 13 months at the secret prison and returned to Yemen where they were charged with forging false travel documents, Amnesty said.

"We argue that you can't have a system of secret detention centers without secret flights to get them there," said Anne FitzGerald, a senior adviser at Amnesty International's London headquarters.

The CIA declined to comment on the report.

Rendition is a process during which terror suspects are transferred to third countries for interrogation, and where some are allegedly subjected to torture. Clandestine facilities allegedly run by the CIA are often referred to as black sites.

The U.S government has said that renditions are carried out according to U.S. law and with its obligations under international law.

The Council of Europe, the continent's top human rights watchdog, called for a probe into the secret prisons. Its report, released last month, did not produce any evidence of secret prisons on European territory.

The Amnesty report also said the CIA is exploiting a loophole that allows private aircraft to land at foreign airports without having to inform local authorities — unlike government or military planes — and called for inspections of planes suspected of being involved in renditions.

Last week, a report by Cage Prisoners, an organization that campaigns on behalf of detainees at Guantanamo Bay, said the CIA has used between 26 and 30 planes for the alleged rendition program and that the flights have passed through British airports en route to various places around the world.

Amnesty's branch in the Czech Republic said three planes made a total of 20 landings in the capital Prague and then took off as part of the rendition program.

A Foreign Office spokeswoman, speaking on condition of anonymity according to department policy, said no requests for rendition through Britain have been made since 1998. She also said the United States made no "extraordinary rendition" flights without informing the ministry.

British Transport Secretary Alistair Darling has said six planes — which campaigners allege are used by the CIA — have made 73 flights through Britain since 2001 on journeys to Afghanistan, Jordan, Saudi Arabia and elsewhere.

But he said the government had no evidence to support allegations that the flights were involved in the transfer of terrorist suspects.