SINGAPORE - A secondary school discipline master ironically broke the law at his own workplace when he took multiple upskirt videos of his colleagues and at least seven students.

The married man, a father of three, also committed the offence at other places, including his mother-in-law's home where he targeted a female relative.

Over a period of more than three years, he took a total of 170 upskirt videos of at least 47 different women.

The 49-year-old man pleaded guilty on Friday to three counts of insulting a woman's modesty.

The court heard that on one occasion, a male student from the school was caught and punished for taking two upskirt videos of a teacher.

On the pretext of retrieving evidence of the student's wrongdoing, the man used his own mobile phone to make recordings of the videos that the boy had filmed.

The man then transferred these videos to his hard disk for his own collection.

Details about the teacher and the school cannot be disclosed due to a gag order to protect the victims' identities.

The Ministry of Education (MOE) told The Straits Times in an earlier statement that the man has been suspended from service since July 2018, and is no longer teaching in any school.

Its spokesman said: "MOE takes a serious view of staff misconduct and will not hesitate to take disciplinary action against those who fail to adhere to our standards of conduct and discipline, including dismissal from service."

Deputy Public Prosecutor Yvonne Poon said that between April 18, 2015, and July 11, 2018, the man filmed multiple upskirt videos of numerous women, targeting at least 38 of his colleagues.

To commit the offences, he would set his mobile phone to video-recording mode before inviting a female colleague to his workstation for data entry purposes.

While she was standing at his desk and keying in data, such as attendance records, he would place the device beneath her skirt and record a video without her knowledge or consent.

The DPP added: "The accused only invited female colleagues wearing skirts or dresses over to his workstation for data entry.

"He would not invite female teachers who were wearing trousers, and seldom invited male teachers over to his workstation for data entry."

By using a similar method, the man also filmed multiple upskirt videos of several students.

DPP Poon told District Judge Brenda Tan: "At least seven of the victims were students of the secondary school, which means that they would have been aged 16 or below and especially vulnerable to his predation.

"In committing the offences, the accused exploited their deference to his authority, as well as the trust that their parents reposed in the school and its faculty."

His offences came to light when a female teacher, who was one of the victims, suspected that he had been taking upskirt videos and alerted the police on July 14, 2018.

On Friday, the court heard that the man was suffering from major depressive disorder at the time of his offences.

Judge Tan then called for a report to assess his suitability for a mandatory treatment order (MTO).

Those given an MTO will undergo treatment for their mental condition in lieu of jail time.

The man is expected to be sentenced on Nov 3.

For each count of insulting a woman's modesty, an offender can be jailed for up to a year and fined.