Police investigating allegations of phone hacking by the News of the World have called for patience as they contact almost 4,000 people whose names appear in documents seized in 2006.
The Met's Deputy Assistant Commissioner Sue Akers said she understood people were upset but police needed time.
She said officers were scouring 11,000 pages of notes as well as dealing with more who feared they were targets.
News International said allegations against its paper had been horrifying.
Among them are claims the paper hacked into the mobile phone of murdered schoolgirl Milly Dowler, the families of 7/7 bombing victims and bereaved military families.
According to a Daily Telegraph report, the phone numbers of relatives of service personnel killed in Iraq and Afghanistan were found in the files of private investigator Glenn Mulcaire, who had been working for the News of the World.
Police have not approached relatives of the soldiers but some families say a newspaper has contacted them suggesting they were victims of phone hacking.
Dep Asst Commissioner Sue Akers, who is in charge of the police investigation known as Operation Weeting, said officers had already spoken to many people and would contact others "as quickly as possible".
"I have huge sympathy for those who may have been the victims of phone hacking or intrusion into their private lives," she said.
"It must be incredibly distressing to see details of the information held, or speculation about what may be held, about them in the media. This is forcing them to relive devastating experiences."
"I stand by my commitment that Operation Weeting will contact all those who have some personal contact details found in the documents seized... and my officers are working hard to ensure it is fulfilled as soon as possible," she added.
"This is taking a significant amount of time and resources."
After the allegations were made over bereaved military families, the Royal British Legion announced it was cutting ties with the News of the World as its campaigning partner, saying it was "shocked to the core".
The charity campaigned with the newspaper on Military Covenant issues and was set to mount another joint initiative to save the chief coroner's office from abolition.
Meanwhile, the Independent Police Complaints Commission has been asked to supervise the Met Police's internal investigation into payments by journalists to police for information.
Met Commissioner Sir Paul Stephenson said a small number of officers were alleged to have taken illegal payments. "If true, I will be determined to root them out, find them and put them in front of the criminal court," he said.
In other developments:
Prime Minister David Cameron is consulting MPs about the nature of a public inquiry into the phone-hacking claims, amid support by the deputy prime minister and the Labour leader for a judge-led hearing, with powers to call evidence and examine witnesses under oath
Shares in BSkyB fall on fears that the News of the World phone-hacking scandal could hinder parent company News Corp's bid for the broadcaster
Culture Secretary Jeremy Hunt is set to delay his decision on whether to allow News Corp's bid for BSkyB after receiving 100,000 submissions on the issue
Michael Mansfield QC, who represented Mohamed Al Fayed at the Princess Diana inquest, has been told his phone may have been hacked
The Crown Office say Strathclyde Police have been asked to look at evidence given by witnesses during the Tommy Sheridan perjury trial, in light of recent allegations
Sainsbury's supermarket, O2, Flybe, Specsavers and Dixons follow the example of other companies including Ford and Npower by suspending advertising in the NoW
The government is to urgently review its advertising contracts with the News of the World
Peter Ridsdale, chairman of Plymouth Argyle, tells BBC Radio Devon, his e-mails were hacked into and he is seeking damages from the News of the World following an article published by the paper when he was chairman of Cardiff City
News International is co-operating with a police inquiry into hacking at the News of the World and is conducting its own investigation into the claims.
"If these allegations are true we are absolutely appalled and horrified," the company said in a statement, adding that its "record as a friend of the armed services and of our servicemen and servicewomen, is impeccable".
