"I'm as shocked as anyone by today's arrests but am determined to lead The Sun through these difficult times. I have a brilliant staff and we have a duty to serve our readers and will continue to do that. Our focus is on putting out Monday's newspaper," Sun editor Dominic Mohan said in a statement.

A source said the arrests included the deputy editor, a picture editor and three other senior staff. Police said a serving police officer, and the source said a defence ministry employee, were among the eight people in total police arrested on Saturday.

The Ministry of Defence declined to comment.

The latest arrests at The Sun, Britain's best selling daily newspaper, come after the arrest of four current and former staff at the newspaper last month, raising questions about the publication's viability.

One of Britain's best known publicists, who has represented many celebrities and others featured in The Sun's pages, said, after the closure of The Sun's sister paper The News of the World, in the wake of a phone hacking scandal engulfing News Corp, talk of another major newspaper demise was not unfounded.

"You have only got to look at what happened to the News of the World. It obviously became an embarrassment to Rupert Murdoch. It's not the newspapers that make the big profits for his organisation. So, I think that it's becoming ever more possible that this could happen -- that if this continues, we could see the end of The Sun in this country," Max Clifford said.

Saturday's arrests were the result of information from News Corp's Management and Standards Committee (MSC), a fact-finding group the firm set up in a bid to rescue its ravaged reputation.

"The MSC provided the information to the Elveden investigation which led to today's arrests ... News Corporation remains committed to ensuring that unacceptable news gathering practices by individuals in the past will not be repeated," New Corp said in a statement.

The MSC's work could lead to further damaging revelations about journalists bribing police that could prompt calls for the Sun's demise.

The once hugely popular News of the World was closed last year by Murdoch after accusations that its reporters hacked the mobile phone messages of celebrities and victims of crime caused a public outcry.

Murdoch also owns The Times broadsheet newspaper, which this year admitted that one of its former reporters had hacked a phone, and the Wall Street Journal U.S. financial newspaper.

Meanwhile, U.S. authorities are stepping up investigations, including an FBI criminal inquiry, into possible violations by Murdoch media employees of a U.S. law banning corrupt payments to foreign officials such as police, law enforcement and corporate sources.

Police said 40 people had been arrested in connection with three police investigations into illegal news gathering practices, but that no one had yet been charged.

Allegations of phone hacking at the News of the World prompted Britain's parliament to summon Murdoch and his executive son James to explain themselves last year.

Many inside and outside parliament have long accused Murdoch of wielding too much political influence through his newspapers.

The scandal's most high profile scalps so far include two top police officials, who resigned over the handling of initial investigations into media malpractice; Rebekah Brooks, a former chief executive of Murdoch's London papers; and Andy Coulson, a former Murdoch editor who became Prime Minister David Cameron's media adviser.