The heartbroken family of a mother found unconscious behind the wheel of her vehicle in a supermarket car park, say claims she died from choking on a chicken burger are false.

Leisa Kenney, 47, was found dead inside her car outside Waterford Plaza, at Perth, earlier this month, with initial reports suggesting a half-eaten burger had been found alongside her.

But family members of the mother-of-one say they were told by staff at Royal Perth Hospital an initial autopsy suggests Ms Kenney actually died of a heart attack, after facing a number of health battles in recent years.