Police are encouraging athletics clubs to phase out the use of starter pistols after it emerged that gangsters were converting them into lethal firearms.
Blank firing alarm pistols, which are traditionally used to start races, are harmless and can be bought cheaply and legally for as little as £40.
But organised crime groups, who have been struggling to import illegal firearms, have worked out how to easily convert them into deadly handguns and are using them to bring terror to the streets.
Law enforcement agencies are currently in discussions with manufacturers to find ways of preventing the pistols from being re-purposed and are also asking the Home Office to tighten the current legislation around the devices.
But Scotland Yard said they were also working with the athletics community to encourage them to move away from starter pistols and find alternative ways of signalling Ready, Steady, Go.
Commander Dave McLaren, of the Met's Specialist Crime Command, said: “They are imported legally and there are people intent on converting them and making them into live firing weapons and they are finding their way into the hands of organised crime groups.”
Detective Superintendent Nick Blackburn added: "We have recovered several factories in London and also in Manchester and other areas in the UK where ammunition is being made.
"Blank firing arms are illegal once they are converted and that is relatively easy to accomplish with basic skills.
"We are working with Border Force and the NCA to see whether there is something we can do to prevent these devices from being easily converted.
"We are also looking at the legislative side of things with the Home Office. It's an emerging trend. We are looking at new powers and legislation that might support us in the fight against gun crime.”
He added: “One of the things we are working on is with the athletics associations within the UK because why do you need a blank firing alarm pistol?
“One of the legitimate reasons of course is currently around athletics and I know we have got some athletics association where they are going to move away from that type of blank firing weapon.”
Starter pistols are no longer used at big events such as the Olympics and World Championships, with organisers using sophisticated electronic systems to begin races.
But they remain popular with grass roots athletics clubs as a cheap, simple and effective way of starting a race.
A UK Athletic spokesman said: "As part of ongoing modernisation work going on within the sport, we have been working with the police to look at how we implement new start technology systems, which in turn would reduce the number of pistols required by starters.
"This work has already commenced over recent years with more electronic systems being tested and used across the UK."
The Met Police said they were seizing an illegal firearm more than once a day in London with 443 taken off the streets in 2020