London: A shipment containing several kilograms of Uranium was seized at UK's Heathrow Airport, following which a major counter-terrorism probe was launched, Dailymail Online, the website of the Daily Mail, a tabloid newspaper based in the UK reported on Wednesday.

The Uranium package which was found in the Cargo section of Heathrow was addressed to an Iranian-linked firm in the UK.

The nuclear material is now seen as 'deadly' but the UK-based media agency reported that the uranium was 'not weapons-grade' - and so could not be used to manufacture a thermo-nuclear weapon, as per sources.

According to the British Tabloid newspaper, The Sun, the Uranium containing package originated in Pakistan before landing at Heathrow's Terminal Four aboard an Oman Air passenger flight from Muscat.

Border Force agents placed the consignment in a radioactive chamber and brought in counter-terrorism officers after discovering it was uranium.

"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 29 December 2022," Met Police told MailOnline, the UK based media agency.

"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," Commander Richard Smith said, according to Dailymail Online.

"Although our investigation remains ongoing, from our inquiries so far, it does not appear to be linked to any direct threat. However, we will continue to follow up on all available lines of enquiry to ensure this is definitely the case," the commander said.