BANGKOK (AP) -- Tests conducted by Thailand's government have found that British-made bomb detectors it bought for a total of $21 million have an accuracy rate of only 20 percent, but they will continue to be used, officials said Tuesday.
Thailand has bought more than 700 of the GT200 devices since 2004 at an average price of 1 million baht ($30,000) each, and Prime Minister Abhisit Vejjajiva said no more would be purchased.
Despite the findings, the government will not ban the use of the GT200, which purportedly screens for explosives and narcotics.
The device is made by British company Global Technical Ltd. A BBC expose last month had scientists test several bomb detectors -- including the GT200 -- and they reached a consensus that the devices were worthless and had no scientific basis for working.
Britain banned the export of one such device, called the ADE651, to Iraq and Afghanistan last month after the BBC report. The U.S. military also found that device unreliable, and the Iraqi government, which also uses the ADE651, has launched an investigation.
The test results are likely to embarrass Thailand's army chief, who has defended the gadgets despite domestic criticism.
The blind tests Sunday involved placing an explosive in one of four boxes and pointing the GT200 at all four.
"It turns out the results were only accurate four times out of 20," Abhisit told a news conference. "The government will not approve any further purchases."
Government spokesman Panitan Wattanayagorn said the government has not banned the use of the detectors, which are used primarily by the military and other security agencies.
"Should these agencies wish to continue using the devices, they have to be very cautious when operating them," Panitan said.
Thailand's army uses the detectors to screen for bombs in the Muslim-dominated south, where more than 4,000 people have been killed since an insurgency flared in 2004.
Security officials also used them to screen for explosives when Thailand hosted a summit of 16 Asian leaders in October.
The manufacturers of the GT200 say it is powered by the user's own static electricity. Critics have compared it to a magic wand and a dowsing rod.