Police have arrested a 21-year-old man suspected of secretly filming a woman in the toilets of a primary school in Ma On Shan.
It's understood that the suspect is a student teacher and that his alleged victim is a colleague.
The Education Bureau said the school promptly reported the alleged incident and activated a crisis management team.
Counselling will be offered to teachers and children, it added.
The bureau said that when it comes to such alleged incidents, it reviews a teacher's registration once any legal procedures are completed.
The accused can be struck off or their registration refused even if they are not convicted of an offence, it said.