Judge Yap said in her judgement that the woman’s claims were justified.

The judge noted that the main charge or “sting” which the woman needed to justify was that Dr Ong and Dr Chan had colluded to take advantage of vulnerable female patients, that they used their position as doctors to source for patients to have sex with, and that they exchanged information about these women.

Based on the evidence including what the defendant and Dr Chan said during cross-examination, Judge Yap concluded that the main charge was “substantially” true for the following reasons:

Dr Ong sought to have sex with the woman, who was Dr Chan’s patient, even if they were in a personal relationship. Dr Chan continued to supply the woman with Xanax, a drug to help her anxiety, during their relationship. During cross-examination, Dr Ong admitted that he had suggested Dr Chan, the defendant and another party have group sex. This, the judge said, showed that the woman was “de facto” Dr Chan’s patient and Dr Ong had colluded with Dr Chan to have sex with her.

A series of WhatsApp messages between the two doctors included messages where Dr Ong shared a patient’s contact details with Dr Chan and told him to “feel free to play your game”, and also made a reference to having anal sex with the patient. Judge Yap said that she found Dr Ong’s explanation that this was a bad joke to be “incredulous”. The messages, she said, “clearly show” that the two doctors were colluding to take advantage of a female patient.

The messages also showed that the two doctors were colluding with each other to look for women to have sex. Dr Ong introduced women he was having sex with to Dr Chan, in exchange for him to do the same. In one such instance, he had shared a naked photo of a woman to give Dr Chan a “preview”. Dr Chan admitted that Dr Ong did eventually introduce the woman to him and he went on to have sex with her.

The judge also said she rejected the argument by Dr Ong’s lawyer that there was no proof that the patients whom the doctors had sex with were “vulnerable”.

“The relationship between doctor and patient is necessarily one of trust,” she said. 

A surgeon in private practice has lost his defamation suit against a woman who told other doctors that he and another senior consultant were taking advantage of vulnerable female patients to have sex with them.

Dr Julian Ong Kian Peng, who runs a private practice at Mount Elizabeth Novena Hospital, claimed that his reputation and well-being had suffered distress as a result.

However, his lawsuit, which started in July 2018, was dismissed with costs by District Judge Lynette Yap on April 3. The judge found that the defendant’s claims were justified.

The defendant, Ms Serene Tiong, is a business development manager at Thomson Medical Centre, who had an extra-marital affair with the other doctor in question, Dr Chan Herng Nieng, a senior consultant of psychiatry at Singapore General Hospital (SGH).

She was also his patient at the time.


In particular, she noted that Dr Chan is a psychiatrist whose practice involves patients with mental health issues where a “high level of trust between doctor and patient is required”. 

“To be clear, it is this court’s view that any doctor who seeks to have sex with his patient or pass a patient to another doctor to have sex with that patient, is interacting with a vulnerable person vis-a-vis that doctor,” said Judge Yap.