The Italian high court upheld the conviction of 22 employees of the CIA, CIA station chief Robert Lady and Air Force Col. Joseph Romano in the rendition of Egyptian cleric Osama Moustafa Hassan Nasr.
Nasr, known also as Abu Omar, was taken into custody on 2003 and eventually transferred from a U.S. air base in Italy to Egypt where he said he was tortured by interrogators.
Cesare Bulgheroni, the lawyer representing Romano, was quoted by The New York Times as saying there's a "plan to go forward" with a challenge at the European Court of Human Rights.
Armando Spataro, a Milan prosecutor, was quoted by the Times as saying the controversial U.S. practice was "incompatible with democracy."
No comment was available from the CIA.
The European Parliament passed a non-binding resolution last week to investigate whether the CIA had secret detention facilities in the region. The resolution states that Lithuania, Poland and Romania were called on in particular to encourage or open independent investigations.
The Council of Europe says 14 other countries played roles in the rendition program.