British police threw Rupert Murdoch's scandal-hit News Corp. into fresh turmoil Saturday by arresting five senior staff at the top-selling daily the Sun in a probe into journalists paying police for tip-offs.

The move is part of a wider investigation into illegal news gathering practices that has rocked Britain's political, media and police establishments and last year prompted the closure of the Sun's sister Sunday title, the News of the World.

Saturday's arrests came after the company passed information to the police, a move that infuriated staff and sparked talk of a witch hunt amongst journalists by a proprietor who previously celebrated their work.

Murdoch is due in London next week and is set to meet staff, a source familiar with the situation said.

Four current and former Sun staff had already been arrested last month, and the latest detentions raise questions about the viability of Britain's best-selling daily.

Sun editor Dominic Mohan said he was "as shocked as anyone by [Saturday's] arrests" but determined to keep fulfilling the paper's "duty to serve our readers."

The source said the arrests included the Sun's deputy editor, picture editor, chief reporter and two other senior staff. Police said a serving police officer was among a total of eight people arrested Saturday and later released on bail.

The source said a Defence Ministry employee and a member of the armed forces were the others. The ministry declined comment.

The current staff members who were arrested in January have been suspended by the paper, and the same fate is likely to await those arrested Saturday.

Both sets of arrests resulted from information from News Corp.'s management and standards committee, a fact-finding group the firm set up in a bid to rescue its reputation.

The committee is working alongside up to 100 personnel from top law firms as well as forensic advisers, computer experts and police searching through more than 300 million emails, expense claims, phone records and other documents.

According to people familiar with the work of the committee, the project could take at least another 18 months.

"News Corp. remains committed to ensuring that unacceptable news gathering practices by individuals in the past will not be repeated," News Corp. said in a statement.

Murdoch shut the hugely popular News of the World last year after a public outcry over revelations that its reporters hacked the voicemail messages of celebrities and victims of crime.

He had hoped the newspaper's closure would draw a line under allegations of malpractice, but the arrests of Sun staff have renewed speculation over the future of his newspapers, with rival publications warning of a "crisis" and "staff in uproar."

Murdoch also owns the Wall Street Journal and New York Post among a host of titles across the English-speaking world.