TMZ reports...

The singer-turned-rapper and actor was found dead Saturday at his house in Lancaster, CA ... multiple sources tell us Aaron's body was found in his bathtub. Law enforcement sources tell TMZ they received a 911 call at 11 AM Saturday that a male had drowned in the tub.

Law enforcement sources tell TMZ ... homicide detectives have been dispatched to the scene, but we have no information or evidence of foul play. It's standard operating procedure for homicide detectives to investigate such death scenes.

Aaron had tons of legal and substance abuse issues over the years ... infamously going on "The Doctors" a couple years ago and talking about all the pills he was taking. He also went to rehab numerous times.

AC is survived by his son, Prince.

He was only 34.

omg