NSW Police and the University of Sydney are investigating after a man was allegedly seen filming female students in the women's toilets at the university's Camperdown campus shortly before midday on Thursday.

Police on Friday night released a photo of a man they believe may assist with inquiries. A police statement said officers were told a man entered the women’s bathroom and held a mobile phone over a toilet cubicle door before he was disturbed.

The man is described by police as of Asian appearance, of medium build with black hair. He was reportedly wearing black pants, a black top, a dark grey jacket and white runners, and carrying a light blue backpack. NSW Police said the photograph may assist with their inquiries into the incident.

The University of Sydney said it was cooperating with police and had launched its own investigation. A university spokeswoman said officials were "very concerned by this report, and are looking into it as a matter of urgency," and encouraged anyone who witnessed the incident or believes they were filmed to come forward to the university’s Safer Communities office so appropriate support and information on services can be provided.

A student who said she witnessed the incident told the Daily Telegraph she opened a cubicle door and saw a man holding his phone with his camera app open. "I was in complete shock, I said 'what the hell, what are you doing?'" she said. According to the witness, the man turned, said "I'm sorry, I'm sorry" and attempted to leave. The witness said at least three women were filmed while inside cubicles and that she was now too afraid to use the on-campus toilets.

NSW Police urged anyone with information to contact Crime Stoppers. The force said the matter remained under investigation.

Universities and police routinely advise students and staff to report incidents that may constitute a breach of privacy or other offences so that they can be properly investigated and support services offered. The University of Sydney's Safer Communities office provides specialist support to those affected by on-campus incidents and can advise on reporting options and available welfare services.

The release of the photograph and the university’s appeal for witnesses come as the investigation continues. Police have not disclosed whether any arrests have been made and no charges have been announced.