Rupert Murdoch has said he cannot be held responsible for the scandal at the News of the World, saying he was let down by "people I trusted".
The News Corp boss said he was not aware of the extent of phone hacking there and had "clearly" been misled by some of his staff.
But he said he was "humbled" to have to explain his firm's conduct to MPs
His son James apologised to victims, saying hacking was "inexcusable" and a "matter of great regret".
Rupert Murdoch's appearance before the Commons media committee is the first time he has faced direct scrutiny by MPs during his 40-year media UK career.
Faced with a series of questions from Labour MP Tom Watson, Mr Murdoch paused extensively and his son James made several attempts to intervene.
However. Mr Watson made clear that he wanted to hear answers from the father - whose wife Wendy was in the audience - and not the son.
He added: "Your father is responsible for corporate governance and serious wrongdoing has been brought about in the company.
"It is revealing in itself what he does not know and what executives chose not to tell him."
Rupert Murdoch said his questioning by MPs - which are investigating alleged criminal behaviour at the News of the World and what senior executives knew - was the "most humble day of my life".
The News Corp boss said he was not aware of the extent of phone hacking at the company until earlier this year when it handed over new information to the police - triggering a new inquiry
"I was absolutely shocked, appalled and ashamed when I heard about the Milly Dowler case two weeks ago," he told MPs.
Arguing that he ran a global business of 53,000 people and the paper was "just 1%" of this, he said he was not ultimately responsible for what went at the News of the World.
Asked who was responsible for this he said: "The people I trusted to run it and maybe the people they trusted".
Mr Murdoch said he was focused on his US newspaper interests and that he had "perhaps lost sight" of what was going on at the paper, saying he spoke to the editor "very seldom".
James Murdoch, chairman of News International, said the firm failed to live up to "the standards they aspired to" and was "determined to put things right and make sure they do not happen again".
He added: "I would like to say just how sorry I am and how sorry we are to particularly the victims of illegal voicemail interceptions and to their families."
The two men are being questioned about what they knew about phone hacking at the News of the World and whether MPs and the police were misled about the extent of it.
Rupert Murdoch said he had not been made aware by News International management of out-of-court settlements made to a handful of victims of hacking.
James Murdoch said he was "surprised and shocked" to learn that News International was still paying the legal fees of Glenn Mulcaire - the private investigator jailed for phone hacking in 2006 - while his father said he would like to end this arrangement
In other developments:
A post-mortem is being carried out on the body of former NoW reporter Sean Hoare who was found dead on Monday
The Met Police's public affairs director Dick Fedorcio tells MPs 10 out of 45 members of his department had once worked for the News of the World
Police are examining a laptop and paperwork found in a bin near the London home of Mrs Brooks, items believed to belong to her husband
David Cameron is to return to the UK - cutting short a trip to Africa - to prepare for a Commons debate on the hacking scandal on Wednesday
Asked by MPs about the closure of the News of the World, Rupert Murdoch said this was necessary since it had "lost the trust" of the people after recent allegations and was not done for commercial reasons.
One of the reasons he had been forced to withdraw his bid to take full control of BSkyB, he added, was that its competitors had "caught us with dirty hands and created hysteria".
On his relationships with senior British politicians, he said he had been asked to No 10 "for a cup of tea" by David Cameron shortly after he entered Downing Street as a recognition of his support for the Conservatives before the election.
He said he had been asked to enter Downing Street by the back door - both by Mr Cameron and former prime minister Gordon Brown - because it would attract less attention
The Murdochs initially declined to appear before the committee but changed their minds after they were issued with a summons to attend.
Opening the hearing, culture, media and sport committee chairman John Whittingdale said abuses had been uncovered "which had shocked and angered the country" and it was clear Parliament had been misled by News International staff.
Facing questions from MPs earlier, Met Commissioner Sir Paul Stephenson denied any impropriety in the hiring of former News of the World journalist Neil Wallis to provide media support to the police force but said he now regretted the appointment.
Mr Wallis was recently arrested as part of the phone-hacking inquiry.
Sir Paul, who quit on Sunday amid criticism of his force's handling of the phone-hacking saga, also denied "taking a swipe" in his resignation letter at David Cameron's decision to employ Andy Coulson - Mr Wallis' ex-boss - as an aide.
