FOUR Correctional Services Department (CSD) officers yesterday appeared in Eastern Court in connection with the death of a 20-year-old detention centre inmate. Magistrate Mr Michael Hill transferred the case to the District Court for plea on May 18. Sin Kong-meng was unlawfully killed in the Sha Tsui Detention Centre, Lantau, on August 13, 1991, according to an inquest in March last year. Yesterday in Eastern Court, Chan Sai-cheong, 31, was accused of assaulting Sin, causing him actual bodily harm. Wong Sze-yuen, 29, was accused of attempting to pervert the course of justice. He allegedly told an inmate, Lee Kwok-wai, that if the police asked him whether CSD staff had assaulted Sin he should answer ''no''. Yan Hung-tik, 30, faced four counts of common assault. Two of the charges allege he assaulted Sin. It was also alleged that he assaulted Lee in April 1991, and Wong Yan-kit in July 1991. Kwok Man-yau, 31, faced one charge of common assault on Sin. He also faced a count of attempting to pervert the course of justice. All four defendants are on conditional bail.