Armed police were sent to a pensioner’s house near Devizes when it was discovered the 73-year-old man had ordered an illegal 200,000 volt stun gun over the internet.

But firearms officers were not needed as the grandad was devastated to be told he had broken the law. Detective Sergeant Christina MacDonald, of Melksham CID, said: “We did checks before we went to the house but we didn’t really know what to expect so we had firearms officers outside the house just in case.

“But the elderly man was really upset to be told the gun was illegal in this country even though in Germany, where the website is based, they are not.

“He had never been in trouble with the police before in his life so it was all a bit of a shock.”

He said he wanted the stun gun, which came with a free pepper spray as part of the internet deal, for personal security.

But it is not clear why the pensioner who lives in an ordinary village home close to Devizes felt the need for the gun. It was seized and is being kept at Melksham police station.

The man could still face prosecution for ordering the illegal weapon but the matter is still being considered by Detective Inspector Mark Power.

Wiltshire officers were called in after they were alerted by the UK Boarder Agency at Coventry airport who were suspicious of the package. The seized stun gun is four times more powerful than a police Taser, which delivers 50,000 volts of electricity.

Det Sgt MacDonald said: “This case illustrates the need for better education – this man thought he was buying the items from a legal website and therefore they would be legal here.

"These items can cause serious injury and even death if used in the wrong hands so it is vitally important that members of the public are well informed when browsing websites that sell them.”

It is not illegal to purchase the guns on some European websites but it is illegal to import them.