An Italian judge has decided that Premier Silvio Berlusconi will be called to testify in the trial of 26 Americans and several Italians charged with kidnapping a terror suspect during a CIA operation.

The first trial involving the CIA’s extraordinary rendition programme opened in Italy today, without the presence of any of the 26 American defendants accused of kidnapping an Egyptian terror suspect.

Italian prosecutors today said they were seeking the arrest of four more Americans as part of an investigation into the alleged CIA kidnapping of an Egyptian cleric in Milan in 2003.