News International chief James Murdoch has rejected suggestions the company operated like the Mafia over the phone hacking scandal.
During questioning by MPs, Labour's Tom Watson suggested its UK arm had adopted the "omerta" code of silence.
Mr Murdoch said that was "offensive and not true" and said he was not made aware in 2008 that phone hacking went beyond one rogue reporter.
He also said two former executives had given MPs "misleading" evidence.
The clash with Mr Watson, who has pursued the company over the phone hacking scandal, came halfway through the two and a half hour session.
'Bound by secrecy'
Mr Murdoch repeatedly told the committee he had not been made aware of details suggesting phone hacking went beyond Clive Goodman - the former News of the World royal reporter jailed in 2007 - when he authorised a large out-of-court settlement to footballers' union leader Gordon Taylor in June 2008.
Mr Watson asked if he was familiar with the code of "omerta" - where people "bound together by secrecy" pursued their objectives "with no regard for the law" and suggested that was "an accurate description of News International in the UK".
Mr Murdoch replied: "Absolutely not. I frankly think that is offensive and that's not true."
The MP said the company was facing a series of allegations around hacking and told him: "You must be the first mafia boss in history who didn't know he was running a criminal enterprise."
Mr Murdoch said that was "inappropriate" and said while it was a "matter of great regret" that "things went wrong" at the newspaper, when evidence had come to light "we acted... with great zeal and diligence to get to the bottom of issues to improve the processes to make sure they didn't happen again".
The BBC's political editor Nick Robinson, in the hearing, reported that a fellow MP said "oh come on" when Mr Watson made his mafia claim, whilst others on the committee sighed or "tutted".
Earlier in the hearing Mr Murdoch said he had not been shown a copy of the "For Neville" email - assumed to refer to former NoW chief reporter Neville Thurlbeck, which contained transcripts of voicemail messages revealing that Gordon Taylor's phone had been hacked - at a June 2008 meeting with legal manager Tom Crone.
At that meeting he agreed to authorise an increase in the out-of-court offer to Mr Taylor.
He said he was given "sufficient information to authorise the increase of the settlement offer" but added: "The nature of the so-called 'For Neville' email... any wider spread or evidence or suspicion of wider spread of wrongdoing - none of these things were mentioned to me."
Mr Murdoch denied misleading the committee at a hearing in July, when he said he had not been aware of the email.
Two former NoW executives - former editor Colin Myler and former legal manager Tom Crone - have said they "did inform" Mr Murdoch of it at the time but he told the committee on Thursday: "I believe their testimony was misleading."
MP Tom Watson said Neville Thurlbeck told him that Mr Crone had said he had shown the email to Mr Murdoch - something Mr Crone did not confirm when he gave evidence to the committee.
Mr Murdoch replied: "I really can't say what Mr Crone or Mr Thurlbeck may have discussed but my recollection is very clear."
He was also asked whether he knew about a legal opinion given to the company by solicitors Farrer and Co in 2008 which stated there is "a powerful case that there is (or was) a culture of illegal information access used at NGN [News Group Newspapers] in order to produce stories for publication".
Mr Murdoch told MPs on Tuesday: "It was not shown to me at the time, nor was it described to me in those terms in any way."
He said "clearly" some within the company knew about the legal advice and the "for Neville" email - but "none of those things were made available or discussed with me".
In a statement on Thursday, Mr Thurlbeck said he had compiled a dossier in his defence which "cleared my name and incriminated others" and claimed it had been "suppressed" by the News of the World.
Mr Thurlbeck is on police bail after being arrested on suspicion of unlawfully intercepting voicemail messages and has lodged a claim for unfair dismissal against News International.
Mr Murdoch also said the recent arrest of a journalist on the Sun was a matter of "great concern" but said he had "no knowledge" of other News International papers being involved in phone hacking, aside from the News of the World
He did not rule out having to close The Sun if it was proved to have been involved but said he did not want to prejudge the outcome of investigations: "I shouldn't rule any corporate reaction to behaviour of wrongdoing out. That will be a decision taken at the time."
He also apologised for The Sun's coverage of the 1989 Hillsborough tragedy, in which 96 Liverpool football fans died saying: "I am aware of the concerns and the hurt it caused and it is something we are very sorry for, and I am as well."
Mr Murdoch also said revelations that his company had used a private detective to spy on lawyers acting for phone hacking victims in 2010 was "appalling" and "unacceptable" and apologised to committee member Mr Watson, who had also been put under surveillance in the past.
He also said the use of private investigators on his company's papers had since been "severely restricted".
In July, the News of the World was shut down after it was found to have hacked into the voicemail messages of prominent people, including murdered teenager Milly Dowler. The Metropolitan Police estimate about 6,000 may have had their phones hacked since 2002.
The row has put pressure on James Murdoch's position at News Corp - with nearly 35% of News Corporation investors voting against him being re-elected to the board last month.