A MAN was dumbstruck when he stumbled across a half-naked schoolgirl being 'gang-raped' on the steps of a museum, the High Court heard yesterday. Wong Kong-chung, 33, a salesman, said he watched for about three minutes before dashing to a nearby telephone box to call police. The witness said he knew intuitively the girl was being raped because she appeared to be unconscious. Mr Wong said he peered from behind a flower pot and saw one man apparently 'making love' to the 17-year-old while another squatted at her head. Two others kept lookout. When the first man moved away, another approached the teenager, knelt down, lifted her bare legs and unzipped his trousers. 'I realised that it must be a case of rape so I went to inform the police,' said Mr Wong. The High Court jury was told he came across the scene while searching for a public toilet near the Museum of Art in Tsim Sha Tsui in the early hours of March 9 last year. He said he noticed someone walking up and down near the steps and then saw someone lying on the ground. Mr Wong said that on closer inspection, he saw a man on top of a girl. Both were naked from the waist down. He told the court the girl's leg appeared to be wrapped around the man's waist. 'I felt they might be making love,' he said. 'When I looked on I saw that the leg had dropped down suddenly. I saw the man then lift up the leg and put it back around his waist, against his back.' After a while, the man got to his feet and put his trousers back on, then another man approached. The second man appeared to unzip his trousers, Mr Wong said. The witness said it took him four minutes to call police and return to the scene. When he got back he saw two people supporting the girl. 'She appeared to be very weak all over her body as if she was drunk and would fall down any minute,' he told the court. The court has heard the girl became unconscious after taking drugs, drinking beer and smoking a cigarette. Wong Chuen, 23, a salesman, Tsoi Chi-wai, 19, a hawker, and Raymond Lee Kin-man, 25, a salesman, have pleaded not guilty to rape. Lam Tsz-wah, 22, a karaoke manager, has admitted the charge and is expected to give evidence against the other three. It is alleged only Lam and Tsoi had sex with the girl. The girl's 18-year-old friend told the court the men went berserk after smoking what might have been cannabis. 'They behaved as if they had gone mad,' she told the court. 'I was pushed and they tried to touch me up.' She described one of the men as 'very disgusting' and said he had forcibly kissed her. The court heard the men earlier told the teenagers to trust them because they were 'nice'. The trial before Deputy Judge Burrell continues.