An Italian court has issued three more arrest warrants for suspected CIA agents accused of helping to kidnap a Muslim cleric in 2003.
The cleric is said to have been flown out of the US base in Aviano
The authorities have already ordered the arrest of 19 people suspected of being involved in the abduction of Egyptian Osama Mustafa Hassan.
The suspects are accused of abducting Mr Hassan, also known as Abu Omar, and flying him to Egypt for interrogation.
Correspondents say the case has soured relations between Washington and Rome.
Italy says the alleged operation hindered Italian terrorism investigations.
No arrests have been made. None of the suspects is currently believed to be in Italy.
The latest warrants came after Italian investigators reconstructed the contents of a computer hard-disk belonging to one of the accused, according to the Italian Corriere della Sera newspaper.
Prosecutors believe the operation was part of a US anti-terror policy called "extraordinary rendition".
The policy involves seizing suspects and taking them to third countries for questioning without court approval.
The US has previously acknowledged it sends terror suspects to third countries for questioning, but denies it condones torture.
Mr Hassan, 42, is believed to have been abducted on 17 February 2003, and flown out of the country from a US base in Aviano, north of Venice.
After his release last year, he called his family telling them he had been tortured with electric shocks during his detention.
The CIA has refused to comment on the case and the Italian government has said it had no prior knowledge of the kidnap plot.
Mr Hassan is believed to have arrived in Italy in 1997, where he was granted refugee status.