Toronto police have laid an additional 26 sexual assault charges against an anesthesiologist who practised at North York General Hospital.

Police said Thursday in a news release that most of the alleged assaults also took place at the hospital, with one occurring at the Rice Medicine Professional Corp. at 1333 Sheppard Ave. W., just east of Keele Street.

One assault is alleged to have occurred June 1992. The others are alleged to have occurred between 2006 and February 2010, police said.

The new cases involve 26 female victims, they said.

In March, police announced Dr. George Doodnaught had been arrested and charged with three counts of sexual assault.

At the time, they said Doodnaught had been practising at North York General since 1981. The hospital has said he is no longer working there.

"We are extremely concerned that this number of people has come forward to police with allegations and we understand this is a difficult process for those patients and their families," hospital president and CEO Bonnie Adamson said Thursday in a statement.

"These allegations relate to one physician who is no longer working at the hospital. The allegations have not been proven in court."

Police also said they received a number of calls from individuals in the wake of the arrest announcement.

"Investigators believe there may be more victims," they said.  "Anyone who may have witnessed, heard or seen anything that may assist with this investigation is asked to contact police at 416-808-4040."

North York General has also set up an inquiries phone line: 416-756-6271.

Doodnaught was scheduled to appear in court to answer to these new charges.

No allegations against him have been proven in a court of law.

Kathryn Clarke, a spokesperson for the College of Physicians and Surgeons of Ontario, said Doodnaught stll has a licence to practise in the province but it is her understanding that he has not  been working as a doctor since this matter first arose.

"We are investigating Dr. Doodnaught ... but I can't provide any detail about our investigation," she said. "We can't impose any restrictions ... unless a doctor has been referred to the discipline committee and that can only happen after an investigation has been completed."

With files from The Canadian Press