HAWKESBURY, Ont. - Court documents allege an eastern Ontario doctor killed four people around the same date in 2021.

Dr. Brian Nadler was initially charged with first-degree murder last year in the death of 89-year-old Albert Poidinger at the Hawkesbury and District General Hospital.

At the time, police said they were investigating the doctor in connection with several other deaths at the hospital.

Ontario Provincial Police laid three additional charges of first-degree murder against Nadler on Wednesday, in the deaths of 80-year-old Claire Briere, 79-year-old Lorraine Lalande and 93-year-old Judith Lungulescu. But they declined to provide details on the new charges, including when and where the three died.

Court documents allege Poidinger was killed on March 25, 2021, and the three others “on or about” that date.

The documents say Briere, Lalande and Lungulescu also died in Hawkesbury, Ont.

Nadler's lawyers have said their client maintains his innocence.

In a statement issued Wednesday, Brian Greenspan, David Humphrey and Naomi Lutes said Nadler provided “excellent palliative care” to the four patients, who they said died from COVID-19.

The doctor was released on bail in July of last year, and his lawyers said he was released again under the same conditions after his arrest this week.

Those conditions include that Nadler remain in Canada, reside at an approved address and notify police of any address change. He is also forbidden from practising medicine and from communicating with employees, patients and relatives of patients at the Hawkesbury hospital.

The case is set to return to court on Sept. 7.

This report by The Canadian Press was first published Aug. 19, 2022.