No Illegal Drugs in Amy Winehouse's System at Time of Death, Family Says

Amy Winehouse's body is removed from her north London home Saturday (left) on Saturday July 23, 2011. Her father talks with mourners outside her home Monday (right) on Monday July 25.

The mystery behind Amy Winehouse's death at the age of 27 just deepened.

The soul singer's family says toxicology tests show there were no illegal drugs in her system when she died.

"Toxicology results returned to the Winehouse family by authorities have confirmed that there were no illegal substances in Amy's system at the time of her death," the statement read.

They say the tests showed "alcohol was present," but said it hasn't yet been determined if it played a role in the singer's death last month.

""The family would like to thank the police and coroner for their continuing thorough investigations and for keeping them informed throughout the process," the statement continued. "They await the outcome of the inquest in October."

Previously, The Sun reported that her family believed she was killed not by drugs, but by quitting alcohol cold turkey.

They believe the singer's decision to lay off alcohol completely for three weeks was a lethal "shock" for her tiny body, a source told the paper. Her family believe she was killed by a seizure because her tiny frame could not cope with such a dramatic withdrawal.

"Abstinence gave her body such a fright they thought it was eventually the cause of her death," a source told The Sun.

At Winehouse's eulogy at her funeral, her father Mitch Winehouse dismissed reports she went on a drug and alcohol binge before her death.

Winehouse was found dead in her London home in July a month after she was filmed stumbling and incoherent during a European concert performance. She had a long history of drug and alcohol abuse problems.