On 17 July 1992 Borsellino went to Rome where he was told by Gaspare Mutolo, a Mafia member turned informer, of two allegedly corrupt officials: Bruno Contrada, former head of Palermo Flying Squad, now working for the secret service (SISDE), and anti-Mafia prosecutor Domenico Signorino. Borsellino considered Signorino a friend and was deeply troubled by the allegation. He was further disconcerted when the meeting was interrupted by a call from the Minister of the Interior, Nicola Mancino, requesting his immediate presence. Borsellino attended to discover that Contrada was there, and knew about the supposedly secret meeting with the informer.