Hollywood actress Drew Barrymore's half-sister Jessica, who was recently found dead inside her own vehicle in California, did not commit suicide, her brother insists.

Jessica was surrounded by pills and booze when found dead. Her brother John says revealed that his sister also had meth (methamphetamine) in the car.

"It looks like it was a drug misadventure. Mixing alcohol and pills. I seriously doubt she took her own life," dailymail.co.uk quoted John as saying.