Two European human rights groups say they have lodged a lawsuit over alleged CIA prisoner flights landing in France.
The CIA allegedly used European airports to transfer suspects
They say they want more information on at least two incidents when they believe the CIA used French airports.
Paris-based International Federation for Human Rights and the League of Human Rights have brought the action.
The US has defended its policy of "rendition" to move terror suspects, but reports that the CIA secretly used European airports has caused alarm.
The two rights groups said they wanted "all necessary investigations" to be made by the French legal authorities as soon as possible.
Their statement said they "intend to underline the responsibility of French authorities, have the incidents investigated and prosecute those responsible".
They were acting upon allegations that CIA planes landed at Le Bourget airport, just outside Paris, and Guipavas airport near the western city of Brest between 2002 and this year.
French Foreign Minister Philippe Douste-Blazy confirmed there were "civilian flight plans" for two of the flights, but said the French authorities had no further details.
A lawyer for one of the rights groups, Patrick Baudouin, told French news agency AFP that the lawsuit had been lodged at a court near Le Bourget airport, in the Paris suburb of Bobigny.