Scotland Yard detectives were tonight re-examining whether a series of high-profile individuals and celebrities were victims of phone hacking after fresh evidence emerged.
Senior officers said analysis of documents seized in 2005 alongside new information has led them to take a second look at whether some people may have fallen victim to the intrusive scam.
They admitted the individuals concerned were originally told there was "little or no" information held by police that they had been caught up in the newspaper scandal.
A Metropolitan Police spokesman said although there remains no evidence their voice mails were hacked this is now an "important and immediate" new line of inquiry for investigators.
The spokesman added that police are taking "urgent steps" to contact potential victims and warn them of the new development.
He said: "Having begun an analysis of the documents seized in 2005 alongside the new evidence, the team have been able to make some links not previously identified.
"As a result, the team have also identified some individuals who were previously advised that there was little or no information held by the Met relating to them within the case papers and exhibits and this is now being reviewed.
"At this stage, there is no evidence to suggest that their voice mails were hacked but this will be an important and immediate new line of inquiry.
"As a result detectives are taking urgent steps to advise them of this development at the earliest opportunity.
"If any others are identified as possible victims in due course they will also be contacted."
The Met reopened an inquiry into the actions of staff at the News of the World in 2005 and 2006 almost two weeks ago after receiving "significant new information" from News International.
The decision came amid a steady flow of new revelations about the practice of intercepting the voice messages of high profile people, including politicians, police officers and Royals, using secret industry codes.
A team of detectives at the specialist crime directorate, working under the codenamed Operation Weeting and led by Deputy Assistant Commissioner Sue Akers, is now sifting through a mass of material.
They are comparing the new information with material already held, reviewing every action and decision taken by the original investigation and checking how evidence was catalogued.
Ms Akers said: "I am conscious there remains significant interest in this case and we are determined to ensure that we conduct a robust and thorough investigation which will follow the evidence trail to its conclusion.
"We will build on the previous commitment to all those victims whose phones we already have reasonable evidence to believe may have been hacked by establishing or renewing contact with them.
"With this new investigation we will be as open as we can be and will show them all the information we hold about them, while giving them the opportunity to tell us anything that may be of concern to them.
"In time, we will go beyond this group of individuals and make contact with everyone who had some of their personal contact details found in the documents seized in 2005.
"This will ensure all of those who have been affected in some way are made aware of the information we have found relating to them.
"Until I am satisfied that we have validated the data we are re-examining I am not prepared to discuss any of the numbers involved, but I intend to make this information public at the earliest opportunity.
"This is clearly a major task with a considerable amount of work to be done which will take a significant amount of time and resources.
"We will complete this new investigation as soon as we possibly can, but I am unable to predict at this early stage as to how long it will take to complete.
"It would be inappropriate for me to discuss any further details regarding this case at this time."