The expected arrival of the News Corp. chief executive coincided with calls on Prime Minister David Cameron to speed up an inquiry into the scandal, which could jeopardise Murdoch’s plans to take over a British broadcaster and has raised questions about the relationship between the media and politicians.

News Corp. declined to comment on 80-year-old Murdoch’s agenda three days after he closed the News of the World, the 168-year-old best-selling tabloid newspaper at the heart of the allegations, in what has been widely interpreted as a damage-limitation exercise.

Rebekah Brooks, chief executive of News Corps’ British newspaper arm indicated more revelations may emerge, a recording showed.

“Eventually it will come out why things went wrong and who is responsible. That will be another very difficult moment in this company’s history,” she told the newspaper’s staff on Friday, according to a recording carried by Sky News.

Murdoch has brushed off calls for Brooks to resign due to her editorship of News of the World during some of the alleged hacking incidents. Brooks denies knowledge of the practice.

British police on Friday arrested Andy Coulson, the former spokesman for Cameron who had resigned as News of the World editor in 2007 after one of his reporters and a private investigator were convicted of hacking into the phones of aides to the royal family.

Coulson has also said he knew nothing about the phone hacking.

Cameron announced a full public inquiry into the hacking allegations at a hastily-convened news conference on Friday in which he was forced to defend his judgement in hiring Coulson and admitted politicians had been in thrawl to media for years.

The opposition Labour Party said on Saturday Cameron needed to appoint a judge quickly to get the inquiry going to avoid evidence disappearing, pointing to reports of destroyed e-mails.

“The clock runs out at the end of today,” Labour Deputy Leader Harriet Harman told the BBC. “We ought to take precautionary measures.”

A spokesman for Cameron said he was moving as quickly as possible. “We have already approached the Lord Chief Justice who will propose the judge,” the spokesman said, adding that any destruction of evidence would be a criminal matter.

The Guardian newspaper reported on its website that police were investigating evidence an executive at News International may have deleted millions of e-mails from an internal archive in an apparent attempt to obstruct investigations.

A spokeswoman for News International, Murdoch’s British media arm, said the allegation was “rubbish.” She said: “We are cooperating actively with police and have not destroyed evidence.”

Cameron’s opponents on the left want to block Murdoch’s bid for the 61 percent of broadcaster BSkyB NewsCorp. does not already own on the grounds it would give him too much political clout.

After years of allegations about hacking the voice-mail of celebrities and politicians in search of stories, the scandal reached a tipping point earlier this week when it was alleged that in 2002 the paper had listened to the voice-mail of Milly Dowler, a missing schoolgirl who was later found murdered, and even deleted some of her messages to make way for more.

That claim, and allegations that a growing list of victims included Britain’s war dead and the families of those killed in the 2005 London transport bombings, outraged readers and caused many brands to pull advertising from the title.

A source familiar with his plans said Murdoch, who began his British media arm in the 1960s, was likely to arrive in London on Sunday morning.

Analysts and investors said the 14 billion dollar takeover deal could be jeopardised if British regulators impose tougher rules in response to new concerns around News Corp’s dominance in British media.

Britain’s media regulator said on Wednesday it was monitoring the hacking allegations to see whether it was “fit and proper” for News Corp. to hold a broadcasting licence.

Murdoch, who had spent most of the week at a conference in Sun Valley, Idaho, has kept a low-profile since the scandal erupted. On Thursday, he refused to answer journalists’ questions on the matter, referring them to a Wednesday statement in support of Brooks.

Cameron indicated a new assertiveness toward the Murdoch empire by withholding overt endorsement of News Corp’s bid for BSkyB on Friday.

“This scandal is not just about some journalists on one newspaper,” he said. “It’s not even just about the press. It’s also about the police. And, yes, it’s also about how politics works and politicians too.”

News of the World and other newspapers have been accused of paying the police for information. Police said on Friday they had arrested a 63-year-old man in Surrey, southern England over allegations of inappropriate payments to police. A police spokesman said the man was not a serving policeman.

Police also raided another tabloid, the Daily Star, earlier on Friday over allegations of phone hacking.

Shares in the pay-TV chain fell 7.6 percent after the media ministry also said it would take events at the News of the World into account before giving its approval to the takeover. News Corp. shares in New York lost around 4 percent.

Cameron also criticized Brooks, his friend and neighbor who was Coulson’s predecessor as editor and is now a top executive and confidante of Murdoch. She should have resigned, he said, after closing down the newspaper at a cost of 200 jobs.

The prime minister’s close links with those at the heart of the scandal mean he has been damaged by it but analysts say that with probably nearly four years until a parliamentary election he is unlikely to be sunk by it.

Journalists putting together the final edition of the News of the World for Sunday had an emotional, sometimes angry, meeting with Brooks, who told them, according to a staffer who was present, that the title had become “toxic.”

But the 43-year-old, whose mane of red hair, sharp wit and seemingly charmed relationship with Murdoch have long made her an object of fascination for fellow tabloid journalists, made clear she was staying on to manage News International.

Brooks denied the company, which many assume will fill the gap left by the News of the World by extending publication of its Sun daily to Sundays, was combining a cost-saving measure with a bid to remove a threat to its expansion in television.

The police also face tough questions over why an initial investigation into phone hacking was closed after royal correspondent Clive Goodman and a private detective were jailed in 2007.

Detectives are also now looking into payments, in the tens of thousands of pounds, by journalists to police.

Coulson was bailed until October after nine hours at a London police station. Asked if he was being made a scapegoat for the scandal, he told reporters: “I can’t say any more at this stage. There’s a lot I’d like to say, but I can’t.”

Goodman was re-arrested on Friday to answer questions about alleged payments to police officers. Several other journalists have been arrested in recent weeks as police pursue inquiries. (Additional reporting by Keith Weir, Kate Holton, Mike Collett-White, Mohammed Abbas, Stefano Ambrogi and Yinka Adegoke; Writing by Janet Lawrence and Philippa Fletcher; Editing by Ralph Boulton)