National Crime Agency (NCA) investigators searched an industrial unit in Merton, south London, and found an array of tools and machinery, including parts used in the manufacture of weapons and ammo and blank firers ready to be converted.

More than a hundred rounds of live ammunition, around a thousand rounds of blank firing ammunition ready to be converted, and three potentially functioning converted weapons were also recovered, according to the NCA.

Officers from the NCA armed operations unit had earlier recovered in a car what was believed to be a functioning converted weapon and magazines filled with 9mm ammunition.

Evan Girdlestone, 47, from Colliers Wood, will appear before magistrates Croydon on Monday in connection with the incident, charged with offences under the Firearms Act.