A contrite, yet defiant News Corp. CEO Rupert Murdoch denied any responsibility for the phone-hacking scandal that has embroiled his media empire, telling British MPs he was "betrayed" by some of his staff and was unaware of the practices at the News of the World.

Murdoch, appearing at a House of Commons committee alongside his son James, also a News Corp. executive, reiterated his apology for the actions of some employees at the now-defunct tabloid, saying the eavesdropping plots left him "ashamed" and "humbled."

But the 80-year-old Australian-born mogul testified he hasn't considered stepping down in the wake of the scandal and a revived criminal investigation involving the actions of staff and editors at the paper.

"Because I feel that people I trusted — I’m not saying who, I don’t know what level — have let me down and I think that they behaved disgracefully and betrayed the company and me, and it’s for them to pay," Murdoch told MPs.

FULL COVERAGE: Murdochs testify

Rebekah Brooks' testimony:

"I think that, frankly, I’m the best person to clean this up."

The Murdochs' appearance was followed by former News International executive and News of the World chief editor Rebekah Brooks, who apologized to the committee for the phone intercepts, acknowledged "mistakes" were made under her watch and expressed regret the corporation was "too slow" in responding to revelations about the practices.

Brooks, who resigned last week from her senior position in Murdoch's organization, also told MPs she was aware the News of the World used private detectives.

But she testified the hiring of private investigators was the responsibility of the managing editor, and insisted she only learned in 2006 that a private investigator later convicted of criminal charges in the phone-hacking scandal was working for the paper.

She also denied Tuesday she ever knowingly sanctioned payments to police, despite her previous testimony to U.K. legislators in 2003 that Murdoch's flagship paper had paid police officers for information.

"I can say that I have never paid a policeman myself, I have never sanctioned or knowingly sanctioned a payment to a police officer," she said. "I was referring [in 2003] to the wide-held belief, not widespread practice, and in fact, in my experience of dealing with police, the information they give to newspapers comes free of charge."

Brooks was arrested Sunday and freed on bail in connection with the phone-hacking investigation that has embroiled Murdoch's organization in a firestorm of criticism and raised questions about his empire's connections to and influence over British politicians and police.

Brooks said she intended to answer MPs' questions as openly as possible, while also being mindful of continuing criminal investigations.

"Mistakes have been made, but we are trying to put things right," she told the hearing.

News of the World is accused of hacking into the phones of celebrities, politicians, other journalists and even murder victims. The long-simmering scandal gained heightened interest with the revelation that journalists accessed the phone of Milly Dowler in search of scoops while police were looking for the missing 13-year-old.

Brooks maintained in her testimony on Tuesday that she did not know any phone hacking was going on when she was editor between 2000 and 2003, and called the hacking of Dowler's phone "abhorrent."

Protester aims pie at Murdoch

The committee hearing was briefly suspended following a protester's attempt to hit the media mogul with what appeared to be a plate of shaving foam.

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Murdoch was responding to a final set of questions when the protester, who had been sitting in the audience, lunged toward Murdoch.  BBC political editor Nick Robinson reported that Murdoch was apparently hit  with the shaving foam by a man shouting "Greedy."  The protester was then struck by Murdoch's wife, Wendi Deng, who jumped up to defend her husband.

Murdoch was not injured in the incident.

On Wednesday, London police charged Jonathan May-Bowles, 26, with behaviour causing harassment, alarm or distress in a public place under Section 5 of the Public Order Act.

May-Bowles is due to appear in City of Westminster Magistrates Court on July 29. Media reports earlier identified him as Jonnie Marbles, a British comedian.

The hearing resumed a few minutes after the shaving foam incident.

'Most humble day of my life'

Earlier, Murdoch admitted that testifying before a parliamentary committee was the "most humble day of my life."

But asked if he accepted that he was "ultimately responsible for this whole fiasco," Murdoch replied: "Nope."

"You're not responsible. Who is responsible?" Labour MP Jim Sheridan asked.

"The people that I trusted to run it, and then maybe the people they trusted," Murdoch said.

Murdoch also told the committee there was no evidence his top executives knew anything about the hacking.

He said he did not investigate after learning that Brooks, who resigned Friday, had testified to U.K. legislators in 2003 that Murdoch's now defunct News of the World had paid police officers for information.

Asked by lawmakers why there was no investigation, he said "I didn't know of it." He says the News of the World "is less than one per cent" of his News Corp., which employs 53,000 people.

Murdoch later said that he seldom spoke with the editor of News of the World, estimating they talked about once a month.

"I cannot tell you the multitude of issues that I have to handle every day."

'Lost sight'

He said that perhaps he "lost sight" of the paper because "it was so small in the general frame of our company."

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A man is held by police after he tried to attack News Corp chief executive and chairman Rupert Murdoch with a white substance during a parliamentary committee hearing in London on Tuesday. (Reuters)

Murdoch said he was "shocked, appalled and ashamed" at the hacking of Dowler's phone. He also said he had seen no evidence that victims of the Sept. 11, 2001 attacks and their relatives were targeted by any of his papers.

At the beginning of the hearing, Murdoch interrupted his son to say that this is the "most humble day of my life." But he later said that there has been some hysteria in regards to his competitors' coverage over the scandal.

"They caught us with dirty hands and they built this hysteria around it," Rupert Murdoch said.

He also said he was not informed that his company had paid out big sums — $1.1 million in one case — to settle lawsuits by phone hacking victims.

James Murdoch said his father became aware of the settlement "in 2009 after a newspaper report. It was a confidential settlement.

The younger Murdoch said he was surprised and shocked that his company paid the legal fees for royal reporter Clive Goodman, who was jailed in 2007 for eavesdropping on the voicemails of royal aides. He also said he was "surprised and shocked" to learn some of the legal fees of Glenn Mulcaire, the private investigator also jailed for phone hacking, have been paid by News Corp.

The scandal has already destroyed News of the World, cost the jobs of Brooks and Wall Street Journal publisher Les Hinton, and sunk the elder Murdoch's dream of taking full control of a lucrative satellite broadcaster, British Sky Broadcasting.

Murdoch is eager to stop the crisis from spreading to the United States, where many of his most lucrative assets — including the Fox TV network, 20th Century Fox film studio, the Wall Street Journal and the New York Post — are based.

The emergency session of Parliament before the home affairs committee, which is being televised, was called by Prime Minister David Cameron following a dramatic last few days in the widening scandal.

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James Murdoch said he was surprised and shocked that his company paid the legal fees for two men jailed for their role in phone hacking.

Earlier, former Scotland Yard chief Paul Stephenson told the committee on Tuesday that he resigned his post in the wake of the phone-hacking scandal because he didn't want to become a distraction during the Olympics, which London is slated to host next year.

Stephenson said he decided to resign quickly and ahead of organizing policing for the 2012 Olympics, as speculation continued to swirl about his connection to the scandal.

Questions have been raised about Stephenson's links with Neil Wallis, a former executive of News of the World who was arrested over the scandal. Wallis was employed by the police as a media consultant.

Stephenson said he now regrets the contract was taken on but there was no reason to have any suspicion about Wallis.

"There was no reason to doubt Mr. Wallis at all," Stephenson said.

Stephenson said phone hacking wasn't one of the priorities, compared to high profile murder cases and terrorism. He said he had no reason to doubt the integrity of the 2006 investigation into phone hacking that led to two arrests.

On the weekend, two of London's top police officers —  Stephenson and John Yates, assistant commissioner of Metropolitan Police — resigned. On Monday, it was learned Sean Hoare, the whistleblower reporter who alleged widespread hacking at the News of the World, was found dead at his home in England. His death wasn't being considered suspicious.

Hoare was quoted by the New York Times as saying that phone hacking was widely used and even encouraged at the News of the World tabloid under then editor Andy Coulson, who most recently served as Cameron's communications chief. Coulson is one of numerous people arrested as part of the phone-hacking investigation.

Yates decided two years ago not to reopen police inquiries into phone hacking and police bribery by tabloid journalists, saying he did not believe there was any new evidence. Detectives reopened the investigation earlier this year, and apparently have the names of 3,700 potential victims.

Yates told the committee on Tuesday that had he known then what he knows now, "I would have made a completely different decision."

Parliament was to break for the summer on Tuesday after the hearing. Cameron, speaking in Pretoria, South Africa, said it "may well be right to have Parliament meet on Wednesday so I can make a further statement."

Cameron cut short his visit to South Africa as his government faces a growing number of questions about its cozy relationship with the Murdoch empire.

Police have already arrested 10 people, including other former News of the World reporters and editors.

One, Press Association royal reporter Laura Elston, was cleared by police on Monday. None of the others has yet been charged.

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With files from The Associated Press