THE Vietnamese who refused to testify in a murder trial because of inadequate government protection would have done so had he been told the murder charge would otherwise be dropped, the Commission of Inquiry heard yesterday. Mr Bui Van Xuan was testifying before Mr Justice Kempster on the second day of the public hearings into the bungled trial of Mr Nguyen Van Bau, in which Mr Bui was the key witness to the murder of his cousin, Mr Nguyen Manh Cong in Section 8 of Whitehead in May 1991. Mr Justice Kempster is also charged with looking at the wider and sensitive issue of witness protection. Questioned by his counsel, Mr John McLanachan, Mr Bui revealed exactly what witness protection had been offered to him. His repeated requests to move back from High Island to Whitehead Section 2 were never heeded, despite continued oral and written threats when he was moved to High Island. Although originally moved from Section 2 to High Island because he had been assaulted, Mr Bui felt it was safe to return, as his cousin, Mr Nguyen Khanh, had since become head of the section. It was believed that those involved in his assault had been moved out. Mr Bui said that on September 16 last year, the police had visited him at High Island and promised to move him first to Section 1 of Whitehead and then to Section 6. But Mr Bui said the police seemed to forget their promise and nothing happened, so that when the trial started, he was still in High Island. The trial started on October 19, and the day after the third adjournment on October 24, the Superintendent of High Island offered him sanctuary in either Section 9 of Whitehead or a place in Victoria Prison, which Mr Bui and his family accepted. However, when he was told by a police officer in court two days later that he would only be moved to Victoria Prison for the duration of the trial and then returned to High Island, he told the police that this was not sufficient to allay his fears. Mr Bui said he understood that his transfer to either Victoria Prison or Section 9 of Whitehead would be long term - until he was repatriated. He said he did not understand why a move to Whitehead might pose a problem, and repeatedly denied questions from Mr Graeme Mackay, counsel for Senior Superintendent Ivan Wong of the Correctional Services Department, asking whether he was involved with drugs or in drug trafficking. Earlier, the inquiry heard that on October 30, 1992, four days after the original trial was aborted, Mr Bui sent three letters, to the Superintendent of High Island detention centres, the Lawyer of Hongkong (the Director of Public Prosecutions, Mr John Wood) and Mr Justice Sears, before whom he originally appeared. With all three he pleaded for the case to be re-opened. In the letter to Mr Justice Sears, he said that if he had known Mr Nguyen Van Bau would be allowed to walk free he would have risked his life. ''I was not aware that without testimony of the witness, the so-called alleged 'murderer' might go free,'' he wrote. He explained in the letter that on the previous three occasions when he had complained to the judge, he had instructed the police to provide him and his family with protection. Mr Bui complained that he had not been present in the court room when the prosecution told the judge that no evidence would be offered. He promised that if the case was re-opened he would testify. ''This time I promise to tell the true account connected with this murder case in court, even if the court or police fail to provide me with prompt or effective action,'' he said.