Rupert Murdoch published apologies in British newspapers on Saturday for the phone hacking scandal as the British government played down new revelations about its ties to his embattled empire.

The show of contrition came after a day of bloodletting when Murdoch was hit by the resignation of two top aides: Les Hinton, head of Dow Jones, and Rebekah Brooks, the chief executive of his British newspaper arm, News International.

The move has now exposed the Australian-born media magnate's son and heir-apparent James, who is the chairman of News International and also runs the Asian and European operations of parent company News Corporation.

The crisis meanwhile returned to haunt British Prime Minister David Cameron as it emerged on Friday he had 26 meetings in 15 months with Murdoch chiefs, underscoring the influence Murdoch once wielded over British politics.

Cameron also invited Andy Coulson, his former media chief and one-time editor of the now defunct News of the World tabloid, to his Chequers country retreat in March. The visit was two months after Coulson quit Downing Street.

British Foreign Foreign Secretary William Hague came to Cameron's defence, insisting it was a "normal, human thing" to do. The opposition Labour party has said it shows "extraordinary lack of judgment" by the premier.

"In inviting Andy Coulson back the prime minister has invited someone back to thank him for his work, he's worked for him for several years, that is a normal, human thing to do, I think it shows a positive side to his character," Hague told the BBC.

Coulson was arrested last week in connection with the scandal over alleged hacking and payments to police, one of nine people held since police reopened their investigations in January. He denies the charges.

Downing Street has also disclosed that Brooks received hospitality at Chequers twice last year while Murdoch's son James, the chairman of News International, was there once.

On Saturday, Murdoch abandoned his previously defiant stance and ran full-page adverts in seven national British dailies, apologising for the hacking scandal at the News of the World, which he closed last week.

"We are sorry," the headline of the ads read. They were signed "Sincerely, Rupert Murdoch."

It said: "We are sorry for the serious wrongdoing that occurred. We are deeply sorry for the hurt suffered by the individuals affected. We regret not acting faster to sort things out."

In a further show of contrition, Murdoch on Friday met the parents of murdered teenager Milly Dowler, whose phone was allegedly hacked by the News of the World in 2002, when Brooks was editor of the paper.

The British government has announced a full public inquiry into the scandal.

Rupert Murdoch, James Murdoch and Brooks have all been summoned to testify before British lawmakers on Tuesday.

But the scandal continued to spiral with the news that British actor Jude Law is suing The Sun over phone hacking in 2005 and 2006, when Brooks was editor, in the first such claim against the Murdoch-owned daily.

News International dismissed the claims as a "deeply cynical".

The departures of Brooks and Hinton capped a disastrous week for Murdoch in which he was forced to shut the News of the World, the first British paper he bought, and scrap a buy-out of British pay-TV giant BSkyB.

Brooks denies any wrongdoing, but as editor of the tabloid when Dowler's phone was allegedly hacked, she became a lightning rod for outrage.

The 43-year-old, who started out as a secretary at the tabloid and is viewed almost like a daughter by Murdoch, told News International staff she felt a "deep sense of responsibility for the people we have hurt".

She will be replaced by New Zealander Tom Mockridge, the chief executive of Murdoch-owned satellite broadcaster Sky Italia.

Hours later, Hinton announced his resignation, saying that although he knew nothing of the phone hacking when he was chairman of News International from 1995 to 2007, he must take responsibility for the "unimaginable" pain it caused.

"That I was ignorant of what apparently happened is irrelevant and in the circumstances I feel it is proper for me to resign from News Corp. and apologise to those hurt by the actions of News of the World," he said.

In the United States, the FBI has began probing allegations that Murdoch's US employees may have hacked the phones of victims of the September 11 attacks, dealing a potentially huge blow to his US-based News Corp.