Weapons can cost just £60 on the web

A STUN gun works by shocking the human nervous system with high-voltage electrical charges.

The weapon – illegal to own and import into the UK – scrambles the signals of the brain to the muscles.

Most deliver a shock of around 50,000 volts, although the most powerful can discharge up to one million volts.

The weapons are highly prized by criminals and can be easily imported via overseas mail order websites, for as little as £60.

More than 10,000 such weapons – some even designed to look like iPhones or torches – are believed to be in the hands of criminals who use them as a status symbol, for protection and to enforce debt payments.

Stun guns are prohibited under the Firearms Act, which sets a minimum jail sentence of five years unless a court is satisfied exceptional circumstances exist.