TORONTO -- A Toronto doctor engaged in "sexual impropriety" with a teenage patient during a medical appointment, Ontario's medical watchdog has ruled.

The College of Physicians and Surgeons of Ontario's discipline committee found that Dr. Donato Anthony Ruggiero, 70, put his penis in a patient's vagina during an exam in or around 1986.

The victim, in her late teens at the time of the incident, told the committee she had three medical appointments with Ruggiero to address abdominal pain.

During her third appointment, Ruggiero had her disrobe from the waist down and lie on an examining table with her feet in the table's stirrups, she told the committee.

Sensing something during the exam that "did not feel right," the woman said she looked and saw Ruggiero had his penis halfway into her vagina. She testified the doctor had unzipped his pants, put a condom on and was moaning.

She felt frozen during and "wanted to scream, but it just didn't come out," she told the committee.

The woman told her mother about the incident when she got home but did not report it to police or medical authorities because she thought no one would believe her, she said.

In 2013, the woman talked about the incident with her psychotherapist who, with the woman's consent, reported it to the College of Physicians and Surgeons.

Ruggiero admitted to performing a pelvic exam on the woman but denied any sexual impropriety.

His defence counsel argued that the woman had merely seen Ruggiero's gloved finger and mistaken it for a penis with a condom on due to a sexual trauma she suffered in childhood.

The committee rejected this alternate explanation and said Ruggiero was not a credible witness.

"It was not (Ruggiero's) intention to perform a medically-indicated pelvic examination," wrote the committee in its Aug. 23 decision. "Rather, his true intent was to take advantage and exploit a vulnerable patient by inserting his penis into her vagina for self-gratification."

Ruggiero now faces a penalty hearing.

The committee is part of a regulatory body and its decisions don't require the same level of scrutiny as a criminal court.

Toronto police say no charges have been laid against Ruggiero.