Border Force officers at Heathrow have seized material contaminated with uranium, and counter-terrorism police are investigating.
Scotland Yard said: “We can confirm officers from the Met’s Counter Terrorism Command were contacted by Border Force colleagues at Heathrow after a very small amount of contaminated material was identified after routine screening within a package incoming to the UK on December 29, 2022.”
Commander Richard Smith said: “I want to reassure the public that the amount of contaminated material was extremely small and has been assessed by experts as posing no threat to the public.
“Although our investigation remains ongoing, from our inquiries so far, it does not appear to be linked to any direct threat. As the public would expect, however, we will continue to follow up on all available lines of inquiry to ensure this is definitely the case.
“However, it does highlight the excellent capability we and our partners have in place to monitor our ports and borders in order to keep the public safe from any potential threats to their safety and security that might be coming into the UK.”
The force said the material has been identified as being contaminated with uranium, no arrests have been made and officers are working with partner agencies to investigate and ensure there is no risk to the public.
“However, it does highlight the excellent capability we and our partners have in place to monitor our ports and borders in order to keep the public safe from any potential threats to their safety and security that might be coming into the UK,” the force added.
It is understood that the Home Office does not believe there is any threat to the public.
A Home Office spokesperson said: “We do not comment on live investigations.”
The Sun, which first reported the story, said the package originated from Pakistan and arrived at Terminal 4 on a flight from Oman.
The BBC said the uranium was in a shipment of scrap metal and one line of inquiry was whether it was the result of “poor handling”.
