A leaked story about the reopened investigation into the racist murder of Stephen Lawrence had a "negative" effect on the probe, the officer who led it said today.
Detective Chief Inspector Clive Driscoll, who led the Met's investigation into Mr Lawrence's murder, said the effect of a story in the Daily Mail about advances in the investigation came just hours after a meeting with Mr Lawrence's mother and lawyers.
He told the Leveson Inquiry into press standards that it may have been coincidence that a witness was approached by a suspect in the wake of that story, but it had a negative effect on the investigation.
He said the meeting was held on November 7, 2007, with Mr Lawrence's mother, her solicitors and barristers, several members of his team, and a representative from the CPS.
The meeting finished at 8.30pm, and while he was still on the train home, he received a call saying a story would be running in the Daily Mail the following day.
"It was actually before I got home," he said. "I received a phone call whilst I was on the train that there was an article that was going to be printed the following day which followed the meeting that we had just had, or appeared to follow the meeting.
"The information within the Mail certainly was the information we gave to that meeting, with the exception of the terminology used."
He said he had "nothing but respect" for Stephen Wright, who wrote the article, but the story did affect the investigation.
"I have nothing but respect for Mr Wright, no one has tried harder, no organisation has tried to bring justice to Stephen's parents, but we were getting there, and it was undermining that inquiry, and I can't understand that," he said.
"I have admiration with what the paper did in supporting the family, I have admiration in Mr Wright pursuing it.
"The bit I can't understand is why, when you get there, you would then do anything to undermine it.
"Without confidence the police are about as much use as a chocolate teapot, because we need people to feel confident to come to us, we need people to be able to tell us their story.
"If people feel threatened, and it is a fact that after this report a witness was visited by one of the suspects.
"Now that could have been a coincidence, but I am a police officer so I'm cynical at birth.
"So it had a negative effect on the investigation. It had a negative effect on my team. It had a negative effect on how we reacted to our partners.
"I don't know who leaked this, so therefore everyone became a suspect and that is the negative effect that it has."
Mr Driscoll said he originally took the decision not to speak to the media in the early stages of leading the investigation.
"I think Stephen's investigation has always had a degree of press interest because of the type of murder that it was," he said.
"Certainly, previous investigations had suffered from what are described as leaks which had made the investigation somewhat difficult.
"What I found was that whenever there was an article in the newspaper it almost set a ball rolling, so there became a bit of a frenzy.
"I felt that was not conducive to a good investigation and not helpful when witnesses were making the decision whether to come forward and assist us or not."
He told the inquiry that information was limited to a small number of people, and only certain information was shared with forensic officers.
"We would tell them what they needed to know to allow them to make the investigations that we were asking."
He said that after the article in the Daily Mail on November 8, Mr Wright was spoken to and did not publish a second story.
He also said Mr Wright confirmed that no police source was involved in handing him the information.
The inquiry heard that an article published in the Sunday Times in February 2008 was originally thought to have come from a "leak" but was later found to have come from information released by mistake by a press officer for forensic science service LGC.
Mr Driscoll said he became suspicious of someone leaking information, and leaking it to derail the investigation.
"There was a considerable amount of information being put in which was correct and there was an awful lot of information which was not.
"That information would have made it difficult for witnesses to have confidence to come forward."
He said 48 hours after the Director of Public Prosecutions gave them permission to move forward with arrests, Stephen Wright contacted the Met saying he had information about forthcoming arrests and charges.
On this occasion, again when asked to, the Daily Mail did not publish the story, he told the inquiry.