BANGKOK (AFP) - Thai Prime Minister Abhisit Vejjajiva said Tuesday he had ordered the military to stop buying a British-made bomb scanner after tests proved it performed worse than a sniffer dog. Abhisit said Thailand had already spent at least $21 million on between 700 and 800 of the detectors since 2003. We consider that a sniffer dog is better than the GT200, Abhisit told reporters. Therefore there will be no additional purchases of this machine. Tests on the GT200 were conducted by Thailands Science Ministry over the weekend following warnings by the British government and showed the scanner-detected bombs in only four out of 20 cases. The detectors had already been sent to Iraq and Afghanistan, but Britain has since banned them. They consist of an aerial on a handle, connected to a black box into which substance detection cards are supposed to be placed. They are said to use static electricity to function. Thailands security forces had bought the scanner for use in its far south, where a six-year insurgency has claimed more than 4,100 lives. Abhisit said the Thai government would consider suing the products British maker ATSC, as well as Thai dealer Avia Satcom Co, which sold the scanner to security agencies for an average one million baht ($30,000) each.