The insult came as Murdoch repeatedly denied that he had misled Parliament about his knowledge of phone hacking as he was quizzed again at a Commons Culture Committee hearing.
Labour MP Tom Watson, who has been watched in the past by News International’s private detectives, said: “You must be the first Mafia boss in history who did not know he was running a criminal enterprise.”
Murdoch replied: “Mr Watson, please, that’s inappropriate.”
Watson also produced new evidence from Neville Thurbeck, News of the World’s former chief reporter.
The MP said that Thurbeck had informed him that Tom Crone, the former company lawyer, had seen the “for Neville” email, sent by a junior NOTW reporter to private investigator Glenn Mulcaire in 2008.
Watson asked if News International ran with an “omerta” – a Mafia-style code of silence. He said this was “a group of people who are bound together by secrecy, who together pursue their group’s business objectives with no regard for the law, using intimidation, corruption and general criminality”.
He added: “Would you agree that this is an accurate description of News International in the UK?”
Murdoch refuted the claim, calling it “offensive” and “not true”. He apologised but denied authorising the use of private detectives to follow Watson.
The News International chief laid the blame for the scandal on former editor Colin Myler and lawyer Tom Crone, by claiming there was “inconsistent” evidence to prove to MPs that he knew how widespread the illegal activities were.
Crone responded by saying: “It is regrettable but I can perfectly understand why James Murdoch felt the need to discredit Colin Myler and myself.
“The simple truth is he was told by us in 2008 about the damning email and what it meant in terms of wider involvement.
He now seems to accept he was told of the email, of the fact it contained transcripts of voicemail, and that those interceptions were authorised by the News of the World.
“Perhaps Mr Murdoch could explain who he thought was doing the authorising at the News of the World. At best his evidence on this matter was disingenuous.”
For most of the hearing, Murdoch kept cool and was consistent with his evidence.