James Murdoch has blamed subordinates for keeping him in the dark about illegal behaviour when he ran his father Rupert's UK newspaper empire, and said he did not closely read its now-defunct tabloid the News of the World.
The 39-year-old, once seen as the clear heir apparent to his father's News Corp business, was grilled at a
judicial inquiry into Britain's press culture on Tuesday.
The questioning panel was set up in the wake of revelations that the News of the World illegally hacked into phone messages on an industrial scale to get scoops.
The inquiry, ordered by David Cameron, the British prime minister, will also examine the relationship between the Murdochs and politicians to establish whether these close ties helped journalists feel above the law.
Australian-born Rupert Murdoch, 81, who has seen the scandal erode the formidable political influence he wielded in Britain for four decades, is scheduled to appear before the inquiry on Wednesday and Thursday.
Al Jazeera's Laurence Lee, reporting from London, said that what was really coming out of James Murdoch's testimony was "a bigger conversation inside the courts here about the relationship between the Murdochs and government figures."
James Murdoch, said Lee, insisted that New Corp did not try to seek any corporate influence in return for political support of individual politicians.
"I simply wouldn't do business that way," said Murdoch when questioned on the subject.
But Lee reported that e-mails have been released linking Jeremy Hunt, the country's culture secretary, with an effort to help smooth the way for News Corp to purchase British broadcaster BSkyB.
Opposition politicians are now calling for Hunt to resign, and our correspondent said that more drama was to be expected in the courtroom on Wednesday.
"It does sound like Rupert Murdoch might use this opportunity to get the knives out for the politicians who he thinks, frankly, have betrayed him," said Lee.
Investigations into the scandal have focused on what James Murdoch knew about the illegal phone hacking, especially when he agreed to a large payout to settle a legal claim.
He has consistently maintained that the paper's management failed to alert him to the scale of the problem.
"Knowing what we know now about the culture at the News of the World in 2006, and from what we know about the alleged widespread nature of these poor practices, then it must have been cavalier about risk and that is a matter of huge regret," James Murdoch told a packed courtroom.
Asked if he read the weekly News of the World, he said "I wouldn't say I read all of it", and asked about its daily sister paper, the Sun, he said he had "tried to familiarise myself with what was in it".
The two papers were the biggest sellers in Britain before the Murdochs shut the News of the World at the height of the scandal last year. They have since replaced the News of the World with a Sunday edition of the Sun.
"I wasn't in the business of deciding what to put in the newspapers," Murdoch said.
James Murdoch became chairman of News International in 2007, when he took on the wider job of leading his father Rupert's News Corp in Asia and Europe.
He has argued that the newspaper division was merely a small part of the job and that he could not have been expected to know about the criminality at the title.
Senior managers at the paper have said they informed him of the scope of the problem in an e-mail while they were
negotiating a legal settlement.
James Murdoch is also facing questions about meeting ministers while they considered letting the Murdochs take full control of broadcaster BSkyB, including a Christmas drinks party he attended with Cameron.