The owner of a West Australian funeral business says she was forced to keep the body of a 200-kilogram man in her car overnight with the air conditioner running after a hospital morgue refused to store it because it was "too fat".

Joanne Cummings, the co-owner of Pilbara Funeral Services in Port Hedland, said the Hedland Health Campus had refused to take the bodies of two large people in the past year after claiming it did not have the equipment to accept bodies of such size.

The 'fake fast' diet: fast-track to a smaller waist?

Ms Cummings said the latest incident occurred on Wednesday last week, when she was forced to drive two hours home with a 200-kilogram body in her car before alternative arrangements could be made to store the body.

She told the Port Hedland newspaper the North West Telegraph that she left the air-conditioning in her vehicle running overnight and went through three tanks of petrol trying to keep the body cool. She also checked on the body every 30 minutes.