Rupert Murdoch has admitted that he "failed" to act over the phone hacking scandal that led to the eventual closure of the News of the World.
On his second day of testimony at the Leveson Inquiry into press standards, the media mogul told QC Robert Jay that News International bosses fell victim to a "cover-up" over the hacking scandal.
The proprietor said senior executives were not informed, or misinformed, and "shielded" from what was going on.
"I blame one or two people for that, who perhaps I shouldn't name because for all I know they may be arrested yet," he said.
"But there is no question in my mind that maybe even the editor, but certainly behind that, someone took charge of a cover-up which we were victim to and I regret."
Asked by counsel where the "cover-up" emanated from, the tycoon replied: "I think from within the News of the World. There were one or two very strong characters there who I think had been there many, many years and were friends of the journalists.
"The person I am thinking of was a friend of the journalists, drinking pal, and was a clever lawyer and forbade them to go and see the evidence, or there have been statements reporting that this person forbade people to go and report to Mrs Brooks or James (Murdoch).
"That is not to excuse it on our behalf at all, I take it extremely seriously that that situation had arisen."
Mr Murdoch told the inquiry he had not paid close enough attention to the situation at the now-defunct Sunday tabloid and apologised for what had happened, and to the staff who lost their jobs when he closed the newspaper last July.
"I have to admit that some newspapers are closer to my heart than others but I also have to say that I failed. And I am very sorry about it."
However, the 81-year-old admitted that ultimately "the buck stops" with him. He said he was sorry for the "innocent people" at the News of the World who lost their jobs as a result of the phone hacking scandal, saying he never paid the newspaper enough attention.
Murdoch became riled when giving evidence after Jay suggested his family had wanted a cover up, saying "minds like yours" may think that. He then apologised and withdrew the remarks.
Murdoch also denied that he saw culture secretary Jeremy Hunt as an ally in his company's battle to take over the satellite broadcaster BSkyB. He said he expected Hunt to be a "fairer" judge of the bid than business secretary Vince Cable, who was stripped of the role after being secretly recorded saying he had "declared war" on the News Corp boss.
Murdoch also stood by claims Gordon Brown said he would declare war on News Corp, saying: "As for the conversation, which he's [Brown] denied, I said that very carefully yesterday under oath, and I stand by every word of it."
Later in the testimony, when discussing phone hacking, Murdoch said that what happened at the News of the World was an "aberration", adding that it would be unfair to compare it with The Sun.