A controversial new police communications system is set to be introduced in Hong Kong at a cost of almost HK$1 billion despite health warnings from scientific experts. The state-of-the-art system is understood to have sparked disputes among Hong Kong's high-ranking police officers after the warnings were received. But Assistant Commissioner of Police Peter Halliday, the driving force behind the project, has insisted that the system is safe. However, serious questions remain about the system, which has caused widespread concern among police in Britain, one of the first countries to test it. Two leading international experts on the biological effects of radiation have accused the UK Government of using police as guinea pigs by pushing ahead with the modernisation programme. They are worried that the electromagnetic radiation signals emitted by the system's handsets could damage brain tissue. The Terrestrial Trunk Radio (Tetra) system is a digital communications system that transmits at similar frequencies to mobile phones. It is used by emergency services. Last week the SAR Government formally launched the HK$948 million tender for Tetra. A decision is expected by November. It will be installed over a period of two years, starting late next year. The new system is expected to revolutionise the Hong Kong police force's ageing analogue one, which is often unreliable and open to eavesdroppers. But the decision has not been universally welcomed. One officer said: 'Halliday has faced internal opposition from some quarters about this system. The problem is we just don't know what the health implications of this are.' He said he was sure that once staff groups fully realised the possible dangers of Tetra, opposition would grow. But Mr Halliday, who denied there was any opposition, said: 'We have already introduced this system with the Marine Police and it was welcomed. I should also point out that we have even won awards for it. 'There has been broad support for Tetra because this is the way forward. As a digital system it allows far more penetration [across Hong Kong] and at far lower power, making it more environmentally friendly. 'It is less prone to tampering and eavesdropping and, in fact, we will use encryption so that no one will be able to listen in,' he said. 'You can also send other forms of information because it is digital.' Despite this rebuttal, at least one SAR police staff association has already expressed concern about Tetra and has asked police chiefs a series of questions about the safety and reliability of the system. Some scientists believe that devices such as the Tetra handsets, which pulse data at 17.6Hz, could be harmful, penetrating deep into the brain and damaging cells and synapses. A key report, made by a leading UK scientist two years ago, warned that systems pulsing around 16Hz should be avoided if possible. Alasdair Philips, an expert on this form of radiation, said: 'It is beyond belief that anyone could be contemplating a system like Tetra. 'To design a communications system based on these principles is mind-numbing. The effects we may see could well be on a par with Gulf War syndrome.' Roger Coghill, a scientist who works for the UK Government, said: 'A criminal could not have come up with a better system. They couldn't have chosen a better frequency with which to disarm and debilitate the very forces that are trying to secure their arrest.' Mark Ford-McNicol, of the Overseas Inspectors' Association, said: 'It's early days yet but a few queries have been raised. There have been problems in the US and UK with this type of system. The system can crash pretty quickly if it is overloaded and there is also the health issue.' He said that if there was any truth in the reports then the force would have to proceed with their modernisation programme carefully. Mr Halliday, however, said: 'These issues have been addressed repeatedly by government and independent studies in the UK and they have reached the conclusion that this system is safe. 'The only complaining going on is in the UK from groups with their own agendas, yet you still have Tetra in Europe and there's no furore there.'