Police say a doctor — who allegedly paid to have unprotected sex with a 15-year-old girl in his office at a Toronto hospital — is facing multiple charges.

Toronto police say investigators looking into the alleged trafficking of the girl learned a man met the teen in December 2016 after responding to an escort ad for sex on an online classifieds site.

It’s alleged he had unprotected sex with her and met with her at different hotels in the Toronto area over the next few months and paid to have unprotected sex with the girl.

Investigators allege that after the encounters he would prescribe birth control and inject the girl with the medication.

They allege that on one occasion he had sex with her in his office at Toronto General Hospital.

Ernest Chiu, 32, of Toronto, is charged with sexual interference, invitation to sexual touching, obtaining sexual services from a person under 18 and sexual assault.

Investigators say Chiu is a doctor of nephrology and is associated with St. Michael’s Hospital, Toronto General Hospital, Toronto Western Hospital, Princess Margaret Hospital, Toronto Rehab and Sinai Health System.

According to the College of Physicians and Surgeons of Ontario's records, Chiu studied medicine at the University of Toronto, beginning in July of 2012. His first three years of post-graduate study were in Internal Medicine, followed by two years of Nephrology ending on June 30 of this year. During that time, Chiu was practicing under a postgraduate education certificate.

A specialty in Internal Medicine was issued to Chiu on May 8 of this year.

The College's site, as of Thursday afternoon, lists the terms and conditions of Chiu's certificate of registration as expired.

- With files from Victoria Gibson