There's a complete change in leadership taking place at Ontario's troubled air ambulance system.

The government says it's replacing ORNGE president and CEO Chris Mazza with a deputy minister on an interim basis, but can't say how much severance it will have to pay.

Mazza was being paid $1.4 million a year, but he went on indefinite medical leave days after his salary was made public so it's not clear what severance he will get.

The entire board of directors at ORNGE will also be replaced, and the agency will have to wind up its for-profit side businesses and operate solely as a non-profit entity.

Deputy minister of government services Ron McKerlie will be the interim president and CEO at ORNGE, which will also have to negotiate a new service contract with the province.

The auditor general and the ministry of finance both sent audit teams into ORNGE, which receives about $140 million a year in provincial funding to operate the air ambulance service.