Deputy Assistant Commissioner Sue Akers told the Leveson Inquiry that more than 800 “likely” phone hacking victims had now been identified by the force.
She also told the inquiry that the investigation into alleged phone hacking - one of three major probes into alleged illegal activity - is approaching the “finishing line”.
Operation Weeting began last January after Scotland Yard received “significant” information from News International (NI) - publishers of the now-axed News of the World - relating to the interception of voicemails.
Ms Akers, who is overseeing all three probes, indicated that Operation Weeting was coming to a close.
She said: “We have a number of key witnesses that we will want to see and that process is ongoing now. It will take a few more months.”
Questioning her, Robert Jay QC asked her: “You’re probably nearer to the finishing line than the starting gun, is that right?”
She answered: “I’d like to think so, yes.”
The deputy assistant commissioner said 6,349 potential victims of phone hacking have been identified by name so far.
The telephone numbers of 4,375 of them have been found in documents belonging to private investigator Glenn Mulcaire.
She told the inquiry, sitting at the Royal Courts of Justice in London, that so far Operation Weeting had identified 829 “likely” victims - 581 have been contacted, 231 could not be contacted and 17 have not been contacted for “operational reasons”, she said.
“We have defined likely victims as those that have details around their names that would make it suggest to us that they had either been hacked or had the potential to be hacked,” Ms Akers said.
A total of 17 people have been arrested so far as part of Operation Weeting. No further action is being taken against two, with the remaining 15 currently on bail.
Ms Akers said there are 90 people working on the operation, including 35 tasked with working with the victims.
A total of 300 million emails that were originally thought to be lost have now been recovered and are being examined, Ms Akers said.
She is also overseeing Operation Elveden, looking into allegations that NI journalists made “inappropriate” payments to police.
She revealed the number of Scotland Yard officers assigned to the operation is set to increase.
“We have 40 police officers and staff but we are going to grow the team to take account of the fact that we moved last weekend into an investigation into The Sun, or journalists within The Sun.”
There will eventually be 61 officers working on the operation, she said.
Asked about the progress made so far, Ms Akers replied: “I am less confident in saying that we are near the end than the beginning of Elveden than I was when I made that comment about Weeting.”
The third operation, Operation Tuleta, has been set up to investigate computer hacking. Ms Akers said it is currently at the “scoping” stage and that the force is looking into launching a full investigation.
The Met has faced heavy criticism over the phone-hacking saga which intensified after it failed to reopen inquiries in 2009 amid allegations that thousands of mobiles were intercepted by journalists at the former Sunday tabloid.
Two of its most senior officers sensationally resigned over the scandal.
Then commissioner Sir Paul Stephenson made his shock announcement after coming under fire for hiring former News of the World deputy editor Neil Wallis and accepting free accommodation at a luxury health spa worth thousands of pounds.
Assistant commissioner John Yates handed in his notice the next day following a furore over his handling of a review of the initial hacking probe.
A series of high-profile figures have been arrested in connection with police investigations, including former News International chief executive Rebekah Brooks and ex-Downing Street communications chief Andy Coulson.
Dan Wootton, former showbiz editor at the now-defunct News of the World, said when he joined the newspaper in February 2007, it was made “absolutely clear” that illegal activity would not be tolerated.
“When I joined, obviously it was after Clive Goodman and Glenn Mulcaire had gone to jail, but myself and the rest of the staff were assured that that was an individual case,” he told the inquiry.
“I guess the main thing that was most important to me was that when I started it was made absolutely clear that that sort of behaviour would not be tolerated in any way under (then editor) Colin Myler.”
Mr Wootton said every story, no matter how trivial, would be read by at least four people before it was published.
He said he got stories from celebrities themselves, their public representatives, agents, sometimes friends and family, but had never hacked phones.
“I worked tirelessly to build up these contacts and to gain their trust,” he said.
“I have never hacked a phone, nor done anything illegal in the sourcing of my stories, and there has never been any suggestion that I am implicated in the wrongdoing at the News of the World.”
He said he always gave the subjects of his stories a right of reply - although sometimes the decision was taken above him not to, as it could jeopardise the story.
“There is a need to protect exclusives so, even though I was a big believer in right of reply, in a small number of cases a decision would be taken above me - for commercial reasons usually - that it wasn’t the right decision to give a right of reply, because there was a risk.”
Mr Wootton said if stories were provided to him by freelancers, he made sure they could be verified through valid sources.
He said there were some areas where celebrities’ privacy should be maintained, including sexuality, pregnancies, health matters, and issues involving their children or family.
But he added: “The majority of the celebrities that I would write about were more than happy to be covered because they accepted it was part of the job and they loved their job.”
Mr Wootton, who now does work for the Daily Mail as well as a magazine and a TV show, said he was concerned by a suggestion he said actor Hugh Grant had told the inquiry that his American-based publicists had a blanket policy not to respond if newspapers gave them a right of reply.
“I do believe a right of reply really should go both ways,” he said.
“If a newspaper is giving you the courtesy of a right of reply why should there be a blanket decision never to respond?
“I often think it needs to be a two-way street.”
Sunday Mirror journalist Nick Owens also faced the inquiry today, and denied going on a “fishing expedition” for stories about celebrities undergoing cosmetic surgery.
Mr Owens had a meeting with Chris Atkins, the director of documentary Starsuckers, in which he was told of a fictional contact at a clinic who could provide details about confidential medical information.
The 2009 film planted invented celebrity stories in tabloid papers, Mr Atkins has previously told the inquiry.
Mr Owens was told he could have access to information on cosmetic work undergone by high-profile celebrities, and discussed payment and a confidentiality agreement with Mr Atkins, the inquiry was told.
David Barr, counsel to the inquiry, asked Mr Owens: “Doesn’t this amount to a fishing expedition?”
The tabloid reporter replied: “I wouldn’t say it was a fishing expedition. It was just a meeting in this very informal environment between two people to see whether there would be anything at the end of it that we would want to get involved in publishing.”
He was then asked by Mr Barr: “The nub of it is that you expressed an interest in having confidential medical records and if you couldn’t have those, you would settle for simply being told who had had what surgery?”
Mr Owens replied: “I don’t believe that this is the case. What I was trying to get clear in my mind was the information, the evidence this guy had.”
He said he did not persevere with the story after the meeting because he was concerned that Mr Atkins told him he would get his contact drunk in order to get information from her.
Mr Owens did not mention his discussions with Mr Atkins to his newsdesk and they did not find out about it until Starsuckers was released.
The Sunday Mirror’s editor, Tina Weaver, then called Mr Owens into a meeting and told him he had “acted unwisely and made misjudgments”, the inquiry was told.
During her evidence, Ms Akers said Operation Tuleta is investigating 57 separate allegations of data intrusion, including allegations of phone hacking but more specifically allegations of computer hacking.
She told the inquiry some relate to Met Police inquiries going back as far as the late 1980s.
“Some of them are connected with very historic investigations that the Met has undertaken,” she said.
Ms Akers said the operation so far involved around four terabytes of data: “a huge amount, vast”, she said.
Several allegations have resulted in no further action, she said.
One concerned blackmail in connection with publication of a newspaper story, and another about breach of anonymity under the Sexual Offences Act, but there was insufficient evidence to prosecute.
And one allegation of telephone interceptions against someone awaiting trial for manslaughter was found to be untrue, she said.
She said the operation had a much smaller team working on it - around 20 people.
Prime Minister David Cameron set up the Leveson Inquiry last July in response to revelations that the News of the World commissioned a private detective to hack murdered schoolgirl Milly Dowler’s phone after she disappeared in 2002.
The first part of the inquiry, sitting at the Royal Courts of Justice in London, is looking at the culture, practices and ethics of the press in general and is due to produce a report by September.
The second part, examining the extent of unlawful activities by journalists, will not begin until detectives have completed their investigation into alleged phone-hacking and corrupt payments to police, and any prosecutions have been concluded.