The News of the World paid protection officers for personal details about the Queen and other senior royals, according to emails handed to police.
Detectives are investigating claims that sums of around £1,000 were being offered to police officers in the royal protection branch.
Scotland Yard was informed last month when they were handed a fresh set of documents from News International as part of the long-running phone hacking probe, a source said.
Buckingham Palace, News International and Scotland Yard were unable to confirm the fresh allegations.
One email showed former royal editor Clive Goodman asking then editor Andy Coulson for cash to buy a confidential directory of royal phone numbers, the BBC reported.
Goodman, 53, and Coulson, 43, have been arrested and bailed until October on suspicion of bribing police officers.
Payments surrounding the Sunday tabloid and police first came to light last week as Commissioner Sir Paul Stephenson confirmed emails had been handed over to officers on June 20.
The police chief warned that “anyone identified of wrongdoing” as part of the inquiry “can expect the full weight of disciplinary measures and, if appropriate, action through the criminal courts”..
Former Liberal Democrat leader Sir Menzies Campbell said the latest allegations were “very worrying”.
“It is obviously very worrying indeed,” he told BBC Radio 4’s World at One.
“It must inevitably raise questions about whether or not at any stage the safety of a Royal Family member was put at risk.”
The claims heap more pressure on News International which shut the News of the World after admitting the paper had betrayed its readers’ trust.
Deputy Prime Minister Nick Clegg stepped up pressure on Rupert Murdoch, urging him to do the “decent and sensible thing” by reconsidering his takeover bid for broadcaster BSkyB.
Culture Secretary Jeremy Hunt announced he is seeking fresh advice from Ofcom and from the Office for Fair Trading (OFT) on whether he should refer the bid to the Competition Commission.
In his letter to Ofcom chief executive Ed Richards, Mr Hunt asked whether “any potential future decision in relation to the fit and proper persons test” regarding News Corp might have an impact on the takeover.
The development has prompted a sharp fall in the BSkyB share price which dropped a further 6% to around 700p.
Following a meeting with the parents of Milly Dowler – the murdered schoolgirl whose phone was allegedly hacked by the newspaper while police were searching for her – Mr Clegg said Mr Murdoch should consider the widespread revulsion the disclosures had caused.
“Do the decent and sensible thing, and reconsider, think again, about your bid for BSkyB,” he urged the News Corp chief.
Mr Murdoch last night held talks with some of his most trusted lieutenants after flying into the UK on the day the News of the World was shut down to take personal charge of the crisis.
Among those who met over dinner was News International chief executive Rebekah Brooks – editor of the News of the World at the time Milly Dowler’s mobile phone was hacked.
Ms Brooks has volunteered to speak to police over the wider phone hacking scandal, a News International source said.
Questions have been raised about who at News International was aware of an internal report from 2007 which was only recently passed by the firm to the police.
The Dowler family said Ms Brooks should do the “honourable thing” and quit.
Mr Hunt will give a statement to the Commons on phone hacking and the media this afternoon, parliamentary authorities said.
Scotland Yard said later it was ``extremely concerned and disappointed'' that allegations of payments to corrupt royal protection officers had been leaked to the press, claiming it was an attempt to ``undermine the investigation''.
“It is our belief that information that has appeared in the media today is part of a deliberate campaign to undermine the investigation into the alleged payments by corrupt journalists to corrupt police officers and divert attention from elsewhere,” a statement said.
“At various meetings over the last few weeks information was shared with us by News International and their legal representatives and it was agreed by all parties that this information would be kept confidential so that we could pursue various lines of inquiry, identify those responsible without alerting them and secure best evidence.
“However we are extremely concerned and disappointed that the continuous release of selected information – that is only known by a small number of people - could have a significant impact on the corruption investigation.”