Autopsy shows Hayden Panettiere died from a drug overdose

The US Drug Enforcement Agency (DEA) was reportedly joining the local police department's investigation into the child star's death.Panettiere's ex-boyfriend, Brian Hickerson - who has admitted to abusing her - and his brother Zack were with Panettiere when emergency services came, according to a police report from the day she died.Just months before her death, Panettiere published a memoir where she discussed at length her issues with addiction and postpartum depression. Panettiere has said she was introduced to drugs around the age of 16 during a red carpet appearance for Heroes when a member of her professional team gave her something called a "happy pill" for energy."I had no idea that this was not an appropriate thing, or what door that would open for me when it came to my addiction," she told People Magazine. "As I got older, the drugs and alcohol became something I almost couldn't live without."Panettiere's brother, Jansen, died aged 28 from a heart condition. Panettiere revealed in her book that her brother also struggled with substance abuse and used heroin and cocaine leading up to his death.