A MAN who saw his friend shot dead by police during a Tsim Sha Tsui car chase claimed yesterday he had been killed for merely committing a traffic office. Chan Hon-wing, 34, was driving a white Mercedes-Benz that jumped a set of traffic lights at the junction of Austin and Nathan Roads during the early hours of Saturday. Minutes later he was dead, shot by a police officer whose arm was trapped between the window and the driver's door of the speeding vehicle. Yesterday, a senior police official said the 27-year-old officer involved had genuinely feared for his life when he opened fired. But Chow Man-chiu, 29, who was sitting in the back of the car throughout the incident, will go to the Complaints Against Police Office (CAPO) today and demand to know why his friend was shot. The high-speed chase started at about 3 am on Saturday after officers saw the car jump a red traffic light. It finally stopped at the junction of Austin and Chatham Roads after a five-minute pursuit when, according to police, Chan opened his door. But he then inexplicably drove off, dragging the trapped officer along Chatham Road for about 30 metres before he managed to reach his holster and fire with his standard police issue pistol. Chow said last night: ''I want to ask CAPO why the police shot dead my friend. There was no need to open fire in a traffic offence. ''I'm not sure, but I don't believe the constable was trapped. If he was, then it would have been impossible for him to draw the gun. ''I don't think Chan was in any way threatening the life of the policeman or pedestrians.'' Chow, a company chauffeur, said he, Chan and a third man in the car, Mr Chan Chiu-wing, had left a Nathan Road bar at about 2.30 am. ''Chan had drunk alcohol and he did jump a red light and turn into Austin Road illegally,'' he admitted. ''We were immediately chased by a police car along Austin Road. Our car, which was travelling in the middle lane, reversed because there was a car in front but at that time there was another car behind as well. ''We were finally stopped and a policeman armed with a pistol jumped out of the police car and asked Chan to stop. ''A short while later, I heard a bang and the car drifted slowly towards the inner lane and stopped by the pavement. ''A group of seven to eight policeman pulled us out, beat us up, told us to lie flat on the ground and handcuffed us,'' Chow claimed. The head of West Kowloon Police, Assistant Commissioner Toby Emmet, said yesterday that his officer had been dragged along the road before firing his gun. It was more than just jumping a red traffic light, he said, but refused to elaborate as an investigation was in progress. ''The report on the shooting had been done within 24 hours of the incident. The crime report will take a few days to complete,'' he said. ''The reports will be submitted to me and to the Attorney-General. In addition, an inquest will be carried out. ''But let's not rush into judgement, because investigations always take time. We have to interview all those concerned and so far we have been unable to find an independent witness.'' He urged anyone who might have seen the incident to contact the police on 527 7177. The officer who fired the fatal shot has been granted two days' sick leave after being discharged from hospital on Saturday. He sustained leg injuries during the incident. Mr Chan Chiu-wing was still in fair condition in Prince of Wales Hospital last night, while the uninjured Chow was released on bail of $1,500 and told to report to police again on May 27. Chan Hon-wing leaves a wife, Mrs Chan Tsang Yin-wan, 34, and 14-year-old daughter, Yat-hin. The family last night held a Buddhist ritual at the Tsim Sha Tsui Buddhist Study Centre for Chan. His sister-in-law, Miss Tsang Fung-wan, 32, said she wanted to know what legal rights they had to pursue the matter. ''I'm still wondering whether there was any need for the police to shoot dead my brother-in-law,'' she said. ''After reading press reports and talking to Chow, it seems the police might be misleading the public.'' Legislators have already called for an investigation into the incident, the first in which police have opened fire using their new .38 heavy-barrelled Smith and Wesson revolvers and semi-jacketed hollow-point bullets that were introduced last month to give officers more stopping power. According to police sources, the Mercedes 500 SEC had not been reported stolen, none of the three men in it was wanted by police, they were not armed and there were no drugs or stolen goods in the car. The police do not believe the car was involved in road racing, which frequently takes place in the same area. Legco Security Panel convenor Mrs Elsie Tu has led official questioning of what, at the time, to be a traffic case and why the police felt it necessary to open fire.