An alleged case of fraud is under investigation at Hôtel-Dieu Grace Hospital in Windsor, Ont.
CBC News has learned a woman who worked in the finance department is accused of cashing $400,000 worth of cheques issued by OHIP and meant for doctors at the hospital.
Internal financial controls first detected a problem three weeks ago.
'It's very shocking when you discover something like this is going on, obviously.' —Sue Gibson, hospital CFO
The hospital said it immediately fired the employee and called the Windsor Police Service.
"We're working with the police in the investigation and co-operating fully with them but we're not giving any details right now," said Sue Gibson, chief financial officer at the hospital.
Gibson told CBC News the incident has not impacted patient care.
"This is the first time that I'm aware of anything like this. I've been at the hospital for almost 20 years ... it's very shocking when you discover something like this is going on, obviously," said Gibson.
As of Friday morning, the employee had not been formally charged.