THE murder of a government-employed peace-keeper in Whitehead detention centre has prompted a call for processing and repatriation to be speeded up to diffuse tension among the Vietnamese boat people. Mr Tran Tien Dung, 36, who had been employed by the Correctional Services Department to head a peace and order committee, died after being stabbed in the stomach when he intervened in a fight early yesterday. He was taken to Prince of Wales Hospital, where he was certified dead on arrival. Two other men, Mr Nguyen Van Hoa, 37, and Mr Nguyen Van Ving, 33, were injured in the brawl, which occurred in Section Eight at about 1 am. They remained in fair and satisfactory conditions in Prince of Wales Hospital. Government Refugee Co-ordinator Mr Brian Bresnihan denied that yesterday's murder was ''the tip of the iceberg of a growing problem''. He said violent and serious crime in the camps had declined. However, the number of murders in centres and camps rose from five in 1991 to eight last year. The director of Community and Family Services International, Mrs Jane Warburton, said a ''detention centre culture'' could fuel violence among boat people. ''It is a prison environment and the reaction of people kept in detention for years changes from a situation where there would otherwise be different social controls,'' she said. ''Everyone working in this environment recognises the damage done to people in detention, particularly those who have been there for four or five years. Damage is inevitable, and the quicker they are moved out of that environment the better.'' Mr Bresnihan said the Government moved people out of the camps as quickly as possible. He was disappointed that the number of people leaving Hongkong had dropped to about 2,000 so far this year, compared to 3,700 between January and April last year. Sha Tin's Assistant District Commander (Crime), Detective Superintendent Tony Ku Kin-wa, said they were investigating whether Mr Tran was murdered because he had refused to alter the case report about a fight on Thursday.