After her mother left the consultation room, Dr Cheng asked the teenager to take off her clothes, Patient A told the tribunal. He then stood behind her, reached around her and grabbed her breasts. The patient, now in her 30s, said it seemed like he was fondling her breasts in a squeezing and massaging motion. "She felt uncomfortable and frozen and too scared to say anything or move … she rotated her hips to look at the respondent and noticed that he had an erection," according to the patient's evidence detailed in the tribunal decision. The woman said she did not want to tell her mother, feeling "sick and dirty and the shame and guilt". She saw Dr Cheng again when she had been vomiting and feverish. She said Dr Cheng asked her to take her clothes off including her underwear. Dr Cheng again massaged her breasts, then moved his hands down her abdomen, to her groin, asked her to open her legs and palpated her labia. When she became sexually active at 17 and was concerned about bleeding, pain and whether she had contracted a sexually transmitted infection, Dr Cheng put gloves on and inserted his fingers into her vagina, she told the tribunal.

The second patient was 13 years old and living in public youth housing when she first saw Dr Cheng for bronchitis and a check-up. In a statement to police in 1993, the teenager alleged Dr Cheng carried out a breast examination without a parent or guardian present, using both his hands to massage her breasts for about 10 minutes. He pulled her tracksuit pants and underwear down to the top of her legs and touched her around her pubic bone, she told the tribunal. The teenager told several social workers at the youth home about the encounter and burst into tears. A placement officer told her that Dr Cheng was a good doctor and she should keep seeing him, the patient told the tribunal. The third patient, a woman in her 20s, needed a referral for an X-ray for an injured shoulder.

Dr Cheng asked her to undress, lie on the examination table and remove her bra so he could check her heartbeat. He performed a breast examination and abdominal examination, moving lower to her pubic bone, where he pulled down her underwear until she stopped him, the tribunal heard. The fourth patient presented to Dr Cheng with flu-like symptoms in 2012 when she was 21. Dr Cheng decided to perform a breast exam and put his hand on her right breast. The patient said Dr Cheng told her he felt a lump but did not discuss a possible diagnosis or follow-up. The fifth patient, also in her 20s, presented to Dr Cheng in 2013 after noticing a rash on her stomach and chest pains after a trip to Vanuatu and was worried she had malaria after being bitten by a mosquito on her leg. Dr Cheng pulled down her pants and lifted the crotch of her underwear and inspected her vagina and vulval area without asking permission, and performed chest and cardiograms at a follow-up consultation that required her to remove her bra without an appropriate explanation. The tribunal concluded Dr Cheng had touched the five women "in circumstances where there was no adequate or appropriate clinical reason for doing so, other than sexual gratification".

"The misconduct of which we have found the respondent guilty carries with it sexual connotations of the most serious kind," the decision read. "A medical practitioner, such as the respondent, who has, as we have found, deliberately and intentionally carried out inappropriate examinations in an inappropriate manner for sexual gratification is clearly guilty of professional misconduct. "There can be no motivation for the manner in which the respondent exposed and viewed the bodies of these patients, including sensitive areas, and touched them in circumstances where there was no adequate or appropriate clinical reason for doing so, other than sexual gratification." The tribunal will determine whether Dr Cheng will have his medical registration suspended or will be struck off on May 17 and 18. In 2005, Dr Cheng was found guilty of unsatisfactory professional conduct and/or professional misconduct for inappropriate physical and sexual contact with a patient on about five occasions. He was severely reprimanded, fined $10,000 and conditions were placed on his practice.

In May 2016, the Medical Council of NSW again placed conditions on Dr Cheng's medical registration, including that he not treat or perform any procedures on any female. NSW Police said Flemington Local Area Command were conducting inquiries after receiving reports from the HCCC about the alleged misconduct of a doctor between 1993 and 2013.