A former headmaster faces up to three years in jail for repeatedly molesting a pupil he tutored 26 years ago, a court heard yesterday. Walter Yau Woon-man, 53, pleaded guilty to three counts of indecent assault and will be sentenced on November 21 in Kwun Tong Court, pending a trauma assessment report on the victim. Yau remained in custody after Magistrate Ernest Lin Kam-hung warned that a jail sentence was almost certain due to the seriousness of the offences. Yau sexually molested the victim at her home during private tutorials on three occasions in 1986 and 1987, the prosecution said. The victim, now 36 and married, was first molested aged about 11 years old. She did not tell anyone about the attacks, but continued to endure the trauma they caused, the prosecution said. But after learning that Yau had became headmaster at TWGHs Kwan Fong Kai Chi School, a special-needs school in Shek Kip Mei, the victim decided to speak out. Voicing her concern that Yau would victimise more girls, the victim sought help from a social worker earlier this year. The case was later reported to the police, Yau was arrested and resigned from the school. "Imprisonment is almost certain, which is likely to be no less than three months. But the court needs the trauma assessment report on the victim to come up with a fair sentence," Lin said yesterday. Government lawyer Teresa Kam told the court that the case, for technical reasons, could not be transferred to the District Court, despite the severity of the offence. Yau was technically no longer an accused person since he pleaded guilty before the magistrate last month, Kam said. Therefore, his case would have to remain in the magistrate's court, she said, which means Yau will face a maximum penalty of no more than three years. In the District Court, seven years is the maximum sentence. On its website, TWGHs Kwan Fong Kai Chi School confirmed Yau's resignation last school term, and made reference to his criminal prosecution. It said the school has held meetings with teachers and students' parents to explain the situation.