The 500 fake items, which in total sold for more than �20,000, were seized from a wholesaler in Camden, north London and crushed on Thursday.

Trading standards officers said that a kit melting on a busy road "could lead to a tragedy".

The destruction of the kits marks the launch of National Consumer Week, urging people not to buy imitations.

Ron Gainsford, chief executive of the Trading Standards Institute, said counterfeiting was a problem which affected everyone.

"In the case of the mobile phone hands-free sets seized in Camden, it is easy to imagine that a kit melting on a busy road like a motorway could distract a motorist to such an extent that it could lead to tragedy."

Mr Gainsford said consumers should resist the temptation to buy cheap from outlets such as car boot sales and discount stores.