The body was found inside the parked SUV, which had apparently been set on fire, around 2:30 p.m. on private basketball court on a property at 30100 Miraleste Drive.
The age and gender of the victim were not immediately known.
The homeowners niece, who only wanted to be identified as Julie, said the basketball court is part of her aunt's property. Julie said her aunt told her she was OK and didn't know who the vehicle belonged to.
"The body was badly burned," said Lt. Holly Francisco of the Los Angeles County Sheriff's Department. "It's unsure at this time how the vehicle was set on fire. Our investigators are working with Arson to determin how that fire was started."