Prime Minister under fire after top U.K. cop resigns amid phone hacking scandal

Update: Cameron said to have met with Murdoch executives 26 times in 15 months

Prime Minister David Cameron faced fresh questions on Monday over the phone-hacking scandal convulsing the establishment after Britain's top police officer quit over his ties to Rupert Murdoch's empire.

Scotland Yard chief Paul Stephenson resigned on Sunday over the force's hiring of a former executive at the News of the World, but delivered a parting shot at the premier's own decision to employ an ex-editor of the tabloid as his media chief.

His shock announcement came just hours before police bailed Rebekah Brooks -- who resigned on Friday as head of Murdoch's British newspaper arm -- after she was arrested on suspicion of phone-hacking and bribing police.

Cameron heard about Stephenson's resignation while flying to South Africa where he began a trade visit. The Conservative leader had already decided to cut short his visit to the continent from four days to two as the scandal swirled.

A Downing Street spokesman travelling with Cameron said it was right to continue the trip, saying: "A big part of (his job) is boosting the British economy and making trade links, and that's the purpose of this trip."

In Britain, Home Secretary Theresa May attempted to distance Cameron from the furore which has shut down the News of the World, thrown Murdoch's global business into crisis and implicated British politicians and the police.

"I think the Met is different from government. The Metropolitan Police are in charge, and responsible for, investigating alleged wrongdoings at the News of the World," May said told the BBC on Monday.

"I think it is important to keep a line between the investigators and the investigated."

May defended Cameron's judgment in hiring Andy Coulson, the former News of the World editor who went on to become Downing Street media chief but resigned in January. Coulson was arrested over the scandal earlier this month.

"David Cameron himself has made the point that he gave Andy Coulson a second chance, that second chance did not work and Andy Coulson resigned again," she said.

But in his resignation speech, Stephenson took a sideswipe at the hiring of Coulson and compared it unfavourably with Scotland Yard's employment of Neil Wallis, Coulson's former deputy at the paper.

Wallis was hired in 2009. Scotland Yard reopened the initially botched probe into hacking at the News of the World in January and the scandal exploded on July 4 with reports the paper hacked the voicemails of a murdered girl, Milly Dowler.

"Unlike Mr Coulson, Mr Wallis had not resigned from News of the World or, to the best of my knowledge, been in any way associated with the original phone hacking investigation," he said.

He added that he "did not want to compromise the prime minister in any way by revealing or discussing a potential suspect who clearly had a close relationship with Mr Coulson."

Stephenson was felled by reports Sunday which said the police chief accepted a five-week stay earlier this year at a luxury health spa where Wallis, who himself was arrested last week, was a PR consultant.

The police chief denied any wrongdoing.

Cameron said Stephenson's resignation was "a very sad occasion for him," adding "I wish him well for the future."

May was due to address parliament later Monday over Scotland Yard's employment of Wallis.

Separately Brooks, one of Murdoch's closest lieutenants, was released on bail at around midnight (23:00 GMT Sunday) after 12 hours of questioning over the scandal.

Her spokesman David Wilson said she had been instructed to report back to a London police station in late October.

Wilson warned the arrest could affect her planned testimony before British MPs on Tuesday over the spiralling scandal alongside Murdoch and his son James, the chairman of News International.

Murdoch's US-based News Corp. is in crisis, having also had to abandon its bid for full control of pay-TV giant BSkyB and accept the resignations on Friday of Dow Jones chief Les Hinton, who had worked with him for 52 years.

Brooks, 43, is the 10th person and most senior Murdoch aide to be arrested over the scandal so far. At a previous hearing in 2003 she admitted the paper had made payments to police.

Shares in News Corp. plummeted 5.82 percent in Australian trade on Monday.