Rupert Murdoch was expected to fly into London today to confront the growing News Corporation crisis amid calls for the immediate appointment of a judge to head an inquiry into the phone hacking scandal.
The chairman's anticipated intervention follows reports that millions of emails from an internal archive at News International may have been destroyed in what could be seen as a bid to obstruct Scotland Yard's inquiry.
In a letter to the Prime Minister, shadow culture secretary Ivan Lewis said there should be immediate cross-party discussions with a judge being put in place today.
"In view of the fact that the News of the World is shutting down, it is a matter of great urgency that any documentary evidence, including files and emails, is preserved to enable a proper inquiry into these serious allegations to take place," he told David Cameron.
The letter, which stated that the inquiry's terms of reference should be agreed with the judge "as soon as practicably possible", comes as the latest person held by police in the growing controversy was released on bail.
The 63-year-old man, arrested in Surrey last night in connection with alleged corrupt payments made to police officers, was ordered to return to a London police station in October. Police would not confirm reports that he is a private investigator.
News of the World editor Andy Coulson has also been released on bail following nine hours of questioning over suspected corruption and the phone hacking scandal that forced the 168-year-old newspaper to close.
As Mr Coulson, 43, of Forest Hill, south-east London, left Lewisham police station yesterday, he said: "There is an awful lot I would like to say, but I can't at this time."
The Sunday tabloid's ex-royal editor Clive Goodman, 53, has also spoken to police over claims officers were bribed following a dawn swoop on his Surrey home.
As the crisis at Mr Murdoch's empire deepened, Mr Cameron pledged "no stone would be left unturned," announcing details of two inquiries.
His words followed a report in The Guardian that Scotland Yard was probing claims that a member of staff at News International deleted a host of emails on two occasions at the end of January.
Scotland Yard refused to comment on the allegations, and a News International spokeswoman said: "This assertion is rubbish. We adopted a documented email retention policy in line with our US parent's records management policy. We are co-operating actively with police and have not destroyed evidence."
Meanwhile, more than £1 billion was wiped from BSkyB's market value yesterday amid speculation the crisis could scupper Rupert Murdoch's bid to take full control of the satellite broadcaster.
Number 10 said that it was acting "as rapidly as possible and legally permissible and that the Lord Chief Justice, Lord Judge, had been asked to propose a candidate to lead the inquiry.
A Downing Street spokesman said: "The Prime Minister has announced a judge-led inquiry. We have already approached the Lord Chief Justice who will propose the judge.
"We will continue to proceed as rapidly as possible and legally permissible and engage party leaders as set out by the Prime Minister.
"A major criminal investigation is ongoing by the police. It would be an offence to destroy or conceal any relevant information."