Amy Winehouse was drug-free when she passed away at age 27 in London on July 23.
A rep for the late "Rehab" singer's family confirmed the results of a toxicology test in a statement on Tuesday.
"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 reads.
The Grammy-winning British star had long battled drug and alcohol addiction, but her father Mitch told Us she had kicked the habit three years ago.
Continues the family statement: "Results indicate that alcohol was present but it cannot be determined as yet if it played a role in her death. The family would like to thank the police and coroner for their continuing thorough investigations and for keeping them informed throughout the process. They await the outcome of the inquest in October."
"Three years ago, Amy conquered her drug dependency," Mitch Winehouse told Us Weekly three days after his daughter's body was found in her London apartment. "The doctors said it was impossible, but she really did it. She was trying hard to deal with her drinking and had just completed three weeks of abstinence."
Added the mourning father of his daughter's final days: "She was the happiest she has been for years. She was not depressed."