The individual was arrested under Section 9 of the Terrorism Act 2006 – which covers the making and possession of radioactive devices and materials – after anti-terrorism officers searched an address in Cheshire on Saturday (14 January).
The man has been released on bail until April. Head of the Met Police’s Counter Terrorism Command, Richard Smith, said: "Our priority since launching our investigation has been to ensure that there is no linked direct threat to the public.
"I want to be clear that despite making this arrest, and based on what we currently know, this incident still does not appear to be linked to any direct threat to the public."
