Drew Barrymore's brother breaks silence about their sister's death

Drew Barrymore's half-brother has broken his silence about their sister's death on what would have been her 48th birthday.

The body of Jessica Barrymore, who shared the same father as Drew, was found slumped behind the wheel of her car in National City, California on Tuesday (29Jul14).

Pills were reportedly discovered on the passenger seat and a can of energy drink was wedged between her legs.

An autopsy is currently underway, but her brother John feels sure her death was a "drug misadventure".

He tells the New York Daily News that "some empty vodka bottles (and) a couple bags of meth (methamphetamine)" were also found in the vehicle.

He says, "My guess is that it was the booze and pills, like with (tragic actor) Heath Ledger. I seriously doubt she took her own life... She was a kindred spirit. She knew laughing is what saves us all."

Drew Barrymore previously released a statement, in which she wrote, "Although I only met her briefly, I wish her and her loved ones as much peace as possible and I'm so incredibly sorry for their loss."

Her half-brother doesn't blame the actress for keeping her distance from the family, adding, "I don't blame her (Drew) for being terrified of anyone she's related to. Her parents were pretty toxic."

Jessica Barrymore would have turned 48 on Thursday (31Jul14).