POLICE shot dead an illegal immigrant and critically wounded another following a robbery in Sha Tau Kok yesterday - bringing to eight the number of people killed by officers this year. Three officers opened fire after one of the robbers threatened to kill the hostage he was holding at knifepoint. The abductor was shot in the chest and died on the way to hospital. Another member of the gang was in a critical condition at the Prince of Wales Hospital after being hit in the arm. The third was overpowered and was being held at the Sha Tau Kok police station for questioning. Police defended their actions, claiming the firing of five shots was necessary to rescue the five victims being held by the gang. Sha Tau Kok sub-division Commander John Fuller admitted last night he was involved in the shooting. ''I discharged some rounds but cannot comment further on this investigation as I am involved.'' It is believed Mr Fuller fired two shots, another two shots were fired by a sergeant, and the fifth by a police constable. Officers were called to the house in Tam Shui Hang village at 11.30 am to investigate a report of an armed robbery. A woman claimed her brother-in-law had been threatened by three men armed with knives. The gang had grabbed him from behind and forced him back into the house. When the police arrived at the house four minutes later, one of the robbers had already taken the brother-in-law hostage. ''We tried to reason with them but they would not listen. When one of them started threatening to kill the hostage we had no other option but to open fire,'' said an officer who was called to the scene. ''We had the safety of the five victims to take into consideration, and thankfully they came out of the incident unscathed.'' Investigations later revealed the robbers, all in their 20s, were illegal immigrants who had crossed the border from Hunan last Friday. The officer, who did not want to be named, added the firing of five shots had been justified. ''Officers repeatedly warned the culprits to surrender but were ignored,'' he said. ''Subsequently, five shots were fired in order to rescue the five victims atthe scene.'' According to statistics, police opened fire 30 times in 1992 and 16 times in the first six months of 1993. Yesterday's shooting raised the number killed by police to eight, one more than last year's tally. A spokesman for the police said it was too early to tell if there would be an internal inquiry into the shooting. ''We have to collect more evidence before a decision like that can be made,'' the spokesman said. Legislative Council Security Panel deputy convenor, James To Kun-sun, said last night he would like to get more details from police about ''exactly how they targeted the offenders''. ''I will ask police for a report for the Security Panel. ''It will at least give them a chance to explain the shooting, especially if some legislators or the public have reservations about the legitimacy of what was done,'' he said. The area was cordoned off yesterday afternoon as officers scanned the area for evidence.