A BBC Newsnight investigation has found that a so-called "bomb detector", thousands of which have been sold to Iraq, cannot possibly work.
The ADE-651 detector has never been shown to work in a scientific test.
There are no batteries and it consists of a swivelling aerial mounted to a hinge on a hand-grip. Critics have likened it to a glorified dowsing rod.
Mr McCormick told the BBC in a previous interview that "the theory behind dowsing and the theory behind how we actually detect explosives is very similar".
He says that the key to it is the black box connected to the aerial into which you put "programmed substance detection cards", each "designed to tune into" the frequency of a particular explosive or other substance named on the card.
He claims that in ideal conditions you can detect explosives from a range of up to 1km.
The training manual for the device says it can even, with the right card, detect elephants, humans and 100 dollar bills.
Claims of such almost magical technical abilities would almost be comic, if the potential consequences were not so serious.
The ADE-651 has been sold to a range of Middle Eastern countries and as far afield as Bangkok for eye-watering prices.
Iraq paid around $40,000 for each device.