Britain's parliament was to hold an emergency debate on Wednesday as a top-selling tabloid newspaper owned by Rupert Murdoch's News International was implicated in claims that families of terror victims and a murdered teen had had their phones hacked.
The scandal has prompted calls for the resignation of a well-connected Murdoch executive and provoked a public outcry that could damage the paper's sales.
Revelations that the News of the World may have accessed the voicemail messages of crime victims - including an abducted 13-year-old girl later found murdered - have caused outrage in Britain and brought to a head a long-running saga previously thought to have targeted celebrities and other high-profile figures.
Three hours of parliamentary time had been cleared for the debate on Wednesday where some politicians have said they could call for a national boycott of the News of the World.
Automaker Ford has already said it would pull advertising from the News of the World (NotW) until it saw how it deals with the matter. Other companies said they were reviewing the situation.
News International, which also publishes Murdoch's stable of British newspaper titles including The Times and The Sun, said new information had recently been provided to police.
"Full and continuing cooperation has been provided to the police since the current investigation started in January 2011," it said in a statement.
"Well understood arrangements are in place to ensure that any material of importance to which they are entitled is provided to them.
"We cannot comment any further due to the ongoing investigations."
The BBC said the material passed to police related to a trail of emails appearing to show that payments were made to police in the past for information and that were authorized by former NoW editor, Andy Coulson, later David Cameron's head of communications.
Coulson resigned as News of the World editor in 2007 and has insisted he knew nothing about the phone hacking.
It is not the first time a News Corp paper has been linked to police payments. In 2003, Rebekah Brooks, then editor of The Sun, told a parliamentary committee that her paper paid police for information. News International later said this was not company practice.
QUESTIONS FOR PM
Broadcasters and newspapers rushed to publish new details of a saga that has forced the resignation of Coulson and has now come to the door of Brooks, now head of News Corp's British newspaper arm. She is a frequent guest at the country home of Prime Minister David Cameron.
The Daily Telegraph newspaper reported that News of the World journalists may have attempted to access voice messages left on phones as relatives waited for information about their loved ones in the aftermath of the London bombings in 2005, when British Islamists carried out suicide bombings on the transport network, killing 52 people.
The Independent newspaper said Brooks commissioned a search, on a personal matter, by one of the private investigators used by the News of the World to trace the family of the murdered schoolgirl, Milly Dowler.
The Guardian said police investigating the phone-hacking claims were turning their attention to high-profile cases involving the murder or abduction of children since 2001.
The parents of two murdered schoolgirls in another high-profile case dating back to Brooks' editorship of the News of the World have been visited by police investigating the phone-hacking affair.
Cameron is likely to face intense questioning over the issue at the weekly prime minister's questions session in parliament on Wednesday, particularly his friendship with Brooks and her successor Coulson.
Cameron said on Tuesday he was "appalled" by the allegations that in 2002 the murdered schoolgirl's voicemail messages had been listened to and deleted by a News of the World investigator, misleading police and her family.
Cameron's government is weighing approval of News Corp's takeover bid for British broadcaster BSkyB. The hacking revelations are unlikely to derail that deal since approvals are focused on whether the takeover will give Murdoch too much power over the British media. The government has said it does not believe it will.
Murdoch transformed the British press landscape in the 1980s during Margaret Thatcher's years as prime minister, bringing in new technology and confronting printers' and journalists' trade unions. He commands audiences with global leaders and, through his media, is seen as one of the world's most powerful men.
Brooks, who has worked for Murdoch for nearly half her life, was previously seen as untouchable because of her close relationship with the News Corp chairman and chief executive.
But popular pressure could prove her undoing if readers, who had largely shrugged off news that investigators accessed the phone messages of royals, footballers and celebrities to break stories, start to desert the Sunday paper.
Facebook and Twitter campaigns have sprung up in the wake of the latest allegation encouraging readers and advertisers to boycott the News of the World.
Sales of News Corp's Sun newspaper never recovered in the city of Liverpool after it offended football fans in the wake of a stadium disaster more than 20 years ago in which 96 people died.
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