The owner of a Australian undertakers 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 body when she delivered it as they didn't have the equipment to handle it.

She was then 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 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.

The following morning, Ms Cummings and her business partner hired a sea container with a chiller in it to store the body, she told the ABC.

“It’s a load of crap … I could probably put a baby elephant in one of those fridges and it’d fit through the door, and they’re refusing entry for a human being," Ms Cummings told the North West Telegraph.