A man sold fake bomb detectors made from plastic and card to governments and armed forces across the globe, a court heard.

Simon Sherrard, 50, of Hill Rise, Hampstead Garden Suburb, earned thousands of pounds be selling scam devices that were made in China for about £5, the Old Bailey was told yesterday on the first day of his fraud trial.

The phony Alpha 6 devices were the size of mobile phones and consisted of a piece of plastic with an aerial, and a slot into which pieces of card were placed.

The card was supposedly programmed to detect different items, including explosives and drugs.

The court heard that the devices could detect substances as small as 15 billionths of a gram at up to 500 metres, using static electricity.

Mr Sherrard denies supplying the Alpha 6 device for fraud. He is being tried alongside Samuel Tree, 66, and his wife Joan, 61, of Houghton Road, Dunstable, who deny making the devices for fraud.

The couple allegedly assembled the devices in their garden shed. Mr Sherrard would then sell them around the world for thousands of pounds, prosecutor Richard Whittam QC said.

Mr Whittam added: “The device does not work and they knew it did not work, but it was made and supplied to be sold for profit.

“The device was called the Alpha 6 Molecular Detector, a revolutionary product for search and detection of specific contraband substances.”

The trial continues.