DETECTIVES believe a pistol speed-loader found near murdered auxiliary constable Ng Ka-wing on Sunday may have been police issue. ''The speed-loader found near Ng's body appears to be CID issue as it is marked DS for 'detective special' and, just like CID speed-loaders, it is slightly smaller than the ones used by uniformed police. ''Everyone throughout the force yesterday had to check to see if any speed-loaders were missing,'' the police source said. Speed-loaders carry six rounds of ammunition and are issued for use in situations, such as shootouts, where loading manually could endanger the officer. The disclosure came as police put aside routine work to concentrate on tracking down Ng's killer. Organised Crime and Triad Bureau (OCTB) head, Detective Senior Superintendent Albert Kwok Cho-kuen, said 150 detectives were investigating the death of Ng, 29, who was stabbed to death while patrolling Pak Tin Estate, Shekkipmei. His .38 service revolver loaded with six rounds of ammunition was snatched by the suspect, believed to have been carrying a survival knife. ''We have accorded high priority to the case because a police officer has died on duty and his loaded service revolver snatched,'' Mr Kwok said. An autopsy revealed Ng had died of multiple stab wounds to his head, neck and chest. ''Each of the seven stab wounds was deadly and one of the wounds was about 15 centimetres deep,'' Mr Kwok said. The last time the OCTB had to pool officers from all four investigative divisions was in July when a Marine Police constable allegedly stole a Sterling sub-machine gun, two revolvers and nearly 400 rounds of ammunition from the armoury of Marine East Divisional Base in Sai Kung. Yesterday, despite extensive inquiries, Mr Kwok admitted there had been no breakthrough. A police car was parked opposite the housing block for the second consecutive day hoping witnesses could come forward. Detectives believe Ng was attacked when he confronted the suspect as he was about to sign the patrol log book on the ground floor of Block 17.