LONDON - James Murdoch defended his record at the head of his father's scandal-tarred British newspaper unit before a U.K. inquiry Tuesday, saying that subordinates prevented him from making a clean sweep at the now-defunct News of the World tabloid. 

Speaking under oath at Lord Justice Brian Leveson's inquiry into media ethics, Murdoch repeated allegations that the tabloid's then-editor Colin Myler and the company's former in-house lawyer Tom Crone misled him about the scale of illegal behavior at the newspaper. 

Leveson asked Murdoch: "Can you think of a reason why Mr. Myler or Mr. Crone should keep this information from you? Was your relationship with them such that they may think: 'Well we needn't bother him with that' or 'We better keep it from it because he'll ask to cut out the cancer'?" 

"That must be it," Murdoch said. "I would say: 'Cut out the cancer,' and there was some desire to not do that." 

The 39-year-old Murdoch said that at the time he had no reason to doubt his subordinates when he took over at News International, which published the News of the World, saying he had repeatedly been told that nothing was amiss. 

"I was given assurances by them, which proved to be wrong," he said. 

Revelations that reporters at the News of the World had hacked into the phones of hundreds of high-profile people, including a teenage murder victim, pushed Murdoch's father Rupert to close the 168-year-old newspaper, triggered three U.K. police investigations, led to more than 100 lawsuits, and launched Leveson's inquiry into media practices. 

James Murdoch has found himself sucked into the center of scandal, with critics saying that he should have found out about the wrongdoing once he took over at News International in December 2007. 

Ben Stansall / AFP - Getty Images

A protestor wearing a mask depicting James Murdoch demonstrates outside London's High Court during his testimony.

The uproar over illegal behavior at the News of the World has already scuttled Murdoch's multi-billion dollar bid for full control of satellite broadcaster British Sky Broadcasting Group PLC. He resigned from his post as chairman earlier this month "to avoid being a lightning rod," he said. 

Murdoch's relationship with politicians also came under scrutiny. 

The American-born News Corp. executive revealed that he'd told Conservative leader David Cameron that The Sun newspaper would endorse the Tories' election bid at a meeting at the George club in London on Sept. 10, 2009. 

The top-selling paper's endorsement was a blow to Britain's Labour Party — and critics claim that it helped secure Tory approval for the potentially lucrative BSkyB bid after they won the election in 2010. 

Murdoch denied the charge Tuesday. 

"I would never have made that kind of a crass calculation," Murdoch said. "It just wouldn't occur to me." 

Murdoch acknowledged talking to Cameron about it at a Christmas dinner in 2010 — after the Tory leader had been elected prime minister — but said it was "a tiny side conversation ahead of a dinner." 

Judge slams Murdoch's Sky News for illegal email hacking

"It wasn't really a discussion, if you will," Murdoch said. 

Cameron, who won power two years ago, has been forced to play down his contacts with the Murdochs and with Rebecca Brooks, a neighbor and frequent guest at his home in the countryside.

Rupert Murdoch, who is still chairman and chief executive of News International's parent company News Corp., is scheduled to appear before the inquiry on Wednesday. 

U.S.-based News Corp, owner of Fox Television and the Wall Street Journal, was thwarted in its ambition last year to buy the 61 percent of BSkyB, a major British pay-TV provider, that it did not already own. Amid the fire storm of scandal at the News of the World, it withdrew the bid.

Reuters and The Associated Press contributed to this report.

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LONDON – The scandal that has shaken Rupert Murdoch's media empire in Britain has taken a new twist, with police saying that messages missing from a murdered girl’s cell phone could have been deleted automatically rather than being erased by journalists trying to create more space for new calls.

Outrage over allegations that News of the World staffers had deleted the messages while police were searching for 13-year-old Milly Dowler – revealed earlier this year in an article in The Guardian newspaper – contributed to the closure of the tabloid, Murdoch's largest-circulation publication, in July 2011. Apart from the demise of the paper, the public outcry caused by the revelations resulted in the setting up of a public inquiry looking into the behavior of the press.

Dowler had been missing for a few days when activity on the phone’s message system gave her family false hope that the girl was alive and checking her voicemail. Her body was found about six months after she went missing, in March 2002.

However, Glenn Mulcaire, the private detective at the center of the scandal who was employed by the News of the World to help journalists hack phones, has always denied he was responsible for deleting the messages, which was alleged to have been done in order to free up space in Dowler’s mailbox.

And on Monday police backed his statement. Police officers told the Levenson Inquiry into media ethics and standards that they do not have evidence that Mulcaire or the paper’s journalists did the deleting.

One explanation is that the voicemail messages were deleted by the mobile phone provider as their time expired. 

"It is conceivable that News International journalists deleted the voicemails, but the Metropolitan Police Service have no evidence to support that,” Neil Garnham of the Metropolitan Police testified in a statement to the inquiry Monday. He added that the “most likely explanation” was that the messages were automatically removed after 72 hours since that was "a standard automatic function of that voicemail box system at the time.”   

‘The Fake Sheikh’
Also featured at the inquiry Monday was testimony by two of the News of the World's most well-known former reporters. (Previous witnesses include actor Hugh Grant, “Harry Potter” author JK Rowling and the actress Sienna Miller).

The first, Mazher Mahmood, known as the “the Fake Sheikh” for famously disguising himself as a Middle-Eastern businessman and recording conversations with corrupt individuals, claimed his investigations had led to the imprisonment of more than 260 criminals. But his success, he said, had also resulted in multiple death-threats. For this reason his identity was protected at the hearing: journalists were not allowed to attend and the usual video feed from the hearing was shut down (only his voice could be heard).

Mahmood defended practices at the newspaper, saying that the “ends justified the means” when a criminal was arrested as result of their reporting. But he admitted processes to ensure a story was both in the public interest and the source was credible were not as developed at the News of the World as they are at the newspaper where he now works, The Sunday Times (also part of the Murdoch empire). And, though he acknowledged using several covert practices, he denied any knowledge of phone hacking at his former paper.

The second ex-News of the World journalist to appear, Neville Thurlbeck, did not face any questions on phone hacking because he had been arrested in connection with the case and could have been in danger of self-incrimination.

Like Mahmood, he defended practices at the paper, including the kiss-and-tell reports of an affair involving soccer star David Beckham. He said the methods involved in getting the story were justified since the soccer player was trading on his image as a devoted family man to cash-in on huge sponsorships and advertising deals. He confirmed that the woman involved had received a six-figure sum for her story.