Thousands of drivers fined for speeding in the past month may be able to claim refunds after 17 of 40 police laser guns were suspected to have given inaccurate readings. Three guns examined by the University of Science and Technology were found to give unreliable readings. All 17 guns of the same brand, which were made in the US, have now been withdrawn from service pending further tests. Police say they do not know how many tickets have been issued on the basis of faulty evidence from the guns, which have been used since March last year. However, a police spokesman said the guns were regularly tested and the fault had been detected about a month ago. The fault came to light when one of the 17 guns was given to the university's physics department for testing. Chief Superintendent of Traffic, Tang How-kong, said results released last week showed the readings given by the gun were inaccurate. He said the university then conducted tests on two more guns and again found inaccurate readings. All prosecutions and summonses against speeding drivers who had been detected recently by the guns had been suspended. Mr Tang said drivers who suspected they had been issued speeding tickets by the laser guns in the past four weeks could contact the hotline by phoning 2866 8454 or by fax on 2865 0748. They were advised to pay their fines first and then appeal. Mr Tang said the force would refund all fines to drivers if tests found they had been affected by any inaccuracy of the laser guns. All cases that are already in court or in which drivers have paid fines will be reviewed. 'If it's found out any of the laser guns were inaccurate, we will contact each and every driver. All fines which arose from any inaccurate detections will be fully refunded,' Mr Tang said. Police issue about 15,000 speeding tickets every month, with 60 per cent of cases detected by laser guns. This is the second time laser guns have run into problems. Police stopped using them to pinpoint speeding drivers in November, 1999, after a Court of Appeal judge ordered that a convicted taxi driver's case be heard again. Use of the guns resumed in April, 2000, after police examined the force's 23 laser guns. Police said yesterday the suspension of the 17 laser guns would not affect law enforcement with other detectors. They also use 23 guns of another make, several types of radar, visual average speed computers and recorders, and red-light cameras.