(ANSA) - Rome, November 4 - Antonello Nicosia, a senior figure within the Italian Radicals party, was detained on Monday in relation to allegations he acted as messenger for Mafia bosses during prison visits, sources said.

Nicosia was among five people taken to prison in Monday's operation ordered by Palermo prosecutors.

Accursio Dimino, a boss in the Sciacca Cosa Nostra clan who was regained freedom on 2016 after serving two jail terms, was also targeted in the operation.

Nicosia, who is accused of mafia association and aiding and abetting, has been an advocate for prisoners rights for many years.

He allegedly took messages from jailed mobsters during prison visits he conducted thanks to links with MP Giuseppina Occhionero, who was elected as a member of the leftwing LeU group but recently joined the centrist Italia Viva (IV) party, and passed them on to mafiosi in the outside world. Occhionero is not under investigation but she will be questioned as a witness, sources said. In wiretap recordings cited in the detention warrant, Nicosia allegedly insulted slain anti-mafia magistrate Giovanni Falcone and called fugitive Cosa Nostra boss Matteo Messina Denaro "our prime minister".

