Italian authorities have issued arrest warrants for 13 people they claim are agents "linked to the CIA".
The imam was allegedly driven to a US military base after his abduction
The suspects are accused of abducting an Islamic cleric in Milan in 2003 and flying him to Egypt for interrogation.
Osama Mustafa Hassan, also known as Abu Omar, was already being investigated in Italy as part of a terrorism inquiry.
Italian prosecutors believe the operation was part of a controversial US anti-terror policy known as "extraordinary rendition".
The policy involves seizing suspects and taking them to third countries without court approval.
Human rights organisations say some of the countries to which terror suspects have been deported are known to use torture, and critics have branded it "torture by proxy".
The US embassy in Rome has not commented on the arrest warrants issued against the 13 people - 10 men and three women.
Also on Friday, another Milan-based judge issued an arrest warrant for the Egyptian-born imam himself, whose whereabouts are currently unknown.
No arrests have been made. None of the suspects is currently believed to be in Italy.
An Egyptian woman said she had witnessed the abduction of Mr Hassan on 17 February 2003, while he was walking from his house to the mosque where he preached.
She told police he was stopped by two men dressed as police officers, and cried for help in Arabic as he was bundled into a white van.
According to Italian daily Corriere della Sera, Mr Hassan was then driven to the US base at Aviano north of Venice and transferred to another base in Germany, before eventually being taken to Egypt.
The 42-year-old imam called his family in Italy after being released last year, and said he had been tortured with electric shocks during his detention.
Mr Hassan is believed to have arrived in Italy in 1997, where he was granted refugee status.
Italian investigators say his abduction hampered an ongoing investigation into alleged terrorist links.
They managed to track down the 13 suspected agents through the Italian mobiles they used during the operation, the paper says.
The suspects are said to have used US passports to check in at several top-range hotels in Milan.