British prosecutors have charged six men with fraud for selling bomb detectors widely panned as ineffective that were sold to countries including Iraq, officials said Thursday.

The charges follow a 30-month international police investigation into allegations that bogus equipment was sold to more than 20 countries.

Among the accused is millionaire businessman Jim McCormick, 56, of Langport, in southwest England, a director of security firm ATSC who was first arrested in January 2010.

McCormick was remanded in custody after appearing at City of London Magistrates Court Thursday to face six fraud charges.

The charges relate to the fraudulent possession, production and supply of three models of so-called Advanced Detection Equipment -- ADE 101, ADE 650 and ADE 651.

The ADE 651 is a hand-held, pistol-shaped piece of equipment which uses a series of interchangeable credit card size paper cards said to be able to detect explosives such as C4 and TNT, as well as weapons.

It was reputedly sold for between 16,500 and 60,000 dollars per unit, and has become ubiquitous in Iraq, having been bought in large numbers by local security forces.

Britain banned the export of the ADE651 device in 2010 after tests showed it was not suitable for bomb detection.

As McCormick was appearing in court, Britain's Crown Prosecution Service (CPS) announced that five others had also been charged.

"These charges relate to the alleged manufacture, promotion and sale of a range of fraudulent substance detector devices to foreign jurisdictions between 15 January 2007 and 12 July 2012," said senior prosecutor Andrew Penhale.

Gary Bolton, 46, from Kent, southeast England, faces two fraud charges, while Samuel Tree, 65 and Joan Tree, 60, from Bedfordshire, central England, Simon Sherrard, 49, from London, and Anthony Williamson, 57, from Hampshire, southern England, all face one charge each.

The five were released on bail and are due to appear at City of London Magistrates' Court on July 18, while McCormick is due back at the same court on July 19.