Scotland Yard could widen its investigation into hacking, it emerged as Tony Blair and the Duchess of Cambridge became the latest figures to be named as possible victims.
The force said it had received allegations of privacy breaches which fall outside of its ongoing probe into claims that staff at the News of the World hacked into the messages of celebrities, politicians and royals.
It came as the House of Commons heard claims that the former prime minister was targeted by private detective Jonathan Rees.
Labour's Tom Watson told MPs: "The convicted private investigator Jonathan Rees, a contractor to News International, targeted former prime minister Tony Blair for covert surveillance, and at least one former home secretary."
He also told David Cameron during Prime Ministers' Questions that members of the Royal Family may have been subjected to hacking by Mr Rees as well.
He said: "The Metropolitan Police are in possession of paperwork detailing the dealings of criminal private investigator Jonathan Rees. It strongly suggests that, on behalf of News International, he was illegally targeting members of the royal family, senior politicians and high-level terrorist informers."
Prince Edward, the Countess of Wessex, the Duke and Duchess of Kent and former home secretary Jack Straw are said to have been victims of hacking, The Guardian newspaper claimed. And Kate was also said to have been targeted before she married Prince William, it said.
Talking about the allegations on the BBC on Thursday, Mr Blair said he knew no more than what he had read and had not spoken to the Metropolitan Police about it. He added: "I assume that if someone's got something they will get in touch with me."
A Met police spokesman said: "(We) can confirm that since January 2011 the MPS (Metropolitan Police Service) has received a number of allegations regarding breach of privacy which fall outside the remit of Operation Weeting (Scotland Yard's codename for its probe into phone hacking at the News of the World). These allegations are currently being considered."
News of the World publisher News International rejected Mr Watson's claims. A spokesman said: "It is well documented that Jonathan Rees and Southern Investigations worked for a whole variety of newspaper groups. With regards to Tom Watson's specific allegations, we believe these are wholly inaccurate."