A gynaecologist who inaccurately told a nine-year-old girl she was the victim of sexual assault has been disqualified from registering as a health practitioner.

Bruno Giorgio examined the young girl at a regional Victorian hospital in 2018 after she went there with abdominal pain.

He initially tried to assess the girl's genital area in the emergency department, instructing her to remove her underwear through a hand gesture.

When she refused, Dr Giorgio stopped and said he would need to review the girl while she was under anaesthetic.

Dr Giorgio later performed a vaginal examination while the girl was anaesthetised and determined she had the features of someone who had been sexually assaulted.

He told the girl's mother about his findings, saying sexual abuse was the "only possibility" for the vaginal abnormalities.

Dr Giorgio then failed to follow the usual practice of referring the girl to a children's hospital for a forensic examination.

The girl's mother was distressed at the news and sought a second opinion from the Victorian Forensic Paediatric Medical Service.

The service later examined the nine-year-old and found she had no vaginal abnormalities or evidence of recent trauma.

During a hearing at the Victorian Civil and Administrative Tribunal, Dr Giorgio disputed he told the girl's mother sexual assault was the "only possibility".

He also argued he had the adequate experience and knowledge to make his findings.

But the tribunal found Dr Giorgio had engaged in professional misconduct and made findings without adequate experience or knowledge in paediatric gynaecology.

"His misconduct is somewhat extraordinary and ... continues to devastate the family," the tribunal said in its written judgment.

The gynaecologist was also found to have engaged in professional misconduct by prescribing medication to family members and making inappropriate comments to colleagues and patients.

The tribunal reprimanded Dr Giorgio and disqualified him from registering as a health practitioner for 12 months.

He retired from medical practice in 2020 while the Medical Board of Australia was still investigating the allegations.