A nightclub party hosted by MTV and BBC Radio 1 presenter Trevor Nelson was cancelled because of a threat that "violent crime" would take place.
The fifth anniversary party for Nelson's MTV show The Lick, dedicated to R&B music, was due to be held at the Equinox nightclub in Leicester Square, central London, on Monday.
But police received a tip-off and asked the club owners and promoters to call the event off.
Nelson, one of the UK's best-known and most respected R&B presenters, said he would not host any more high-profile events because they attracted too many "idiots".
The Metropolitan Police received criticism after failing to act on a tip-off before one man was shot dead and another injured outside Turnmills nightclub in April.
A spokesman for Scotland Yard said: "We have received several pieces of specific information in relation to this one event.
"The information related to a group of people intending to commit violent crime at this particular event.
"The club owners, at police request, agreed to cancel the event and close the club on the evening in question."
The 2,200 tickets for the event sold out four weeks ago, Nelson told BBC Radio Five Live.
"We're absolutely certain it's nothing to do with the clubbers that are coming to the event," he said.
"It's an ongoing gang war or something in London and there may be people around there."
"Maybe the event was going to be hijacked outside, I don't know."
The first installment of the anniversary party was held in Leeds on Sunday and had police officers and metal detectors on the door.
"It was like going through Heathrow Airport. It was not a pleasant experience," Nelson said.
Large televised gigs in London, Birmingham and Manchester were problematic because gangsters were attracted by the glamour, he said.
"When you do something in London, Birmingham or Manchester you tend to attract problems because they have gun crime," he said.
"Every single event I do now to over 2,000 people in London, Birmingham or Manchester… I won't put them on now."
In the early hours of Easter Monday, 21 April, Jason Fearon, 26, was killed and another man was injured after a group of men forced their way into Turnmills club in central London.
The club was hosting an event organised by R&B promoters Twice As Nice and Radio 1's DJ Spoony and Lisa Maffia, from So Solid Crew, were on the bill.
Scotland Yard later admitted that an anonymous caller warned of the shooting, but the details were not passed on to the right department.