Drew Barrymore’s half-sister Jessica Barrymore has been discovered dead in her car.

Jessica, 47, who had struggled with drug and alcohol addiction, was found slumped at the wheel of her car amidst “dozens of white pills scattered around”, according to a San Diego news station.

• Actress gives dead sister a strange send-off

According to 10News, Jessica’s car was blocking the driveway of an apartment block and residents found her body around 6am when they tried to leave for work.

The Medical Examiner’s Office confirmed to 10News that the woman in the car had the same name and date of birth as the actress’s half-sister.

Drew and Jessica shared the same father, actor John Drew Barrymore.

Like her half-sister, Drew, 39, has also struggled with addiction in the past and had visited rehab twice by the time she was 13.

An autopsy is being conducted to determine the cause of death.