The court document said Squillante, who served a community service sentence for a 1993 fraudulent bankruptcy, made business deals that suggested he might be linked to a Rome-based mafia network allegedly run by one-eyed ultra-rightist Massimo Carminati.
He rented property to a firm owned by convicted murderer Salvatore Buzzi, who is accused of being a prominent member of the crime ring that allegedly skimmed millions of euros off city hall contracts in Rome.
His activities "could raise suspicions of a possible hidden pact between this man and members of organised crime [groups]," the court document said.
During the "Capital Mafia" investigation, police who had tapped Buzzi's telephone recorded him saying the drug trade was less lucrative than schemes involving migrants.
- AAP