The incident was brought to light by an 18-year-old student who filed a report to police in the early hours of yesterday morning saying he had been indecently assaulted by the tutor in a hotel on Hennessy Road in Wan Chai.

The tutor asked the 18-year-old student to go to the hotel so that they could hang out and drink. The student, dazed after being drugged by the man, felt someone touching him. He immediately shouted for help and reported the incident to police at around 3am yesterday. Officers then arrived at the hotel and arrested the 49-year-old man. They seized evidence including a laptop, beer cans, condoms and lubricant.

Police suspected that the tutor drugged the victims with sleep medicines, which he passed off as ordinary supplements. As the victims lost consciousness, he took naked photos of them and indecently assaulted them.

Officers also searched his home and confiscated a hard drive containing over 30,000 photos and videos. The files included around 600 nude photos and videos of the seven victims, as well as 20 videos containing child pornography.

The seven victims, aged from 18 to 22, were former students of the tutor's and were all unconscious when the photos were taken. Officers said they believed they were drugged at that time.

According to the police, the man had been a tutor at an education center for years. He also volunteered as a tutor in a church.

Police added that there could be more than seven victims in this case.

The man was arrested for administering drugs to obtain or facilitate unlawful sexual act, indecent assault and possessing child pornography. He will be remanded in custody overnight.

Police called upon other victims to call 3660 7544 or 3660 7543 and contact officers as soon as possible.