Their report draws largely the same conclusions as that issued by the Council of Europe last week, adding to the embarrassment faced by European governments over possible cooperation with US policies unpopular with domestic opinion.
"In a number of cases, the CIA or other US services have been directly responsible for the illegal seizure, removal, abduction and detention of terrorist suspects on the territory of member states," read the text of the report approved late on Monday by a special committee of the European Parliament.
The committee has heard testimony from several alleged victims and rights groups. While it has no legal powers, it can recommend political actions against any countries found to have been involved, including the United States.
Its report, compiled by Italian lawmaker Claudio Fava, faced nearly 200 last-minute amendments that had to be debated before the committee approved the final text with 25 votes in favour, 14 against and seven abstentions.
Most of the amendments were technical, although one called for further investigations into the alleged existence of a secret detention facility in Kosovo and the possible involvement of KFOR forces in the illegal detention of terrorist suspects.
Another called on EU governments to "take a stronger stance on the closing of the detention centre in Guantanamo Bay and to take a pro-active role in finding a solution for detainees against whom no legal proceedings will be brought".
The report, as amended, will now be submitted to a full session of the European Parliament in early July.
The Council of Europe report said more than 20 mostly European countries colluded in a "global spider's web" of secret CIA jails and flight transfers of terrorist suspects that stretched from Asia to Guantanamo Bay.
"The Fava report makes clear that illegal activities, including rendition of prisoners in the war on terror, took place inside the EU," Jan Marinus Wiersma, a Socialist MP, said.