A small amount of uranium was detected on Dec. 29 in a package that arrived in the UK at London's Heathrow Airport after a routine screening, Sky news reported on Tuesday.

The amount of material was extremely small and has been assessed by experts as posing no threat to the public, the report said, citing Commander Richard Smith, head of London police's Counter Terrorism Command.

Counter Terrorism Policing could not be immediately reached for comment. Heathrow Airport did not immediately respond to a Reuters request for comment.

Uranium can be used for civilian power generation and scientific purposes and is a key ingredient in nuclear weapons. Certain isotopes emit radiation that can be harmful to humans, and the metal itself is toxic if ingested or inhaled.

It does not appear to be linked to any direct threat, although the investigation remains ongoing, Sky news quoted him as saying. (Reporting by Siddharth Jindal in Bengaluru)