08/23/2011 at 10:00 AM EDT
No illegal drugs were in the system of Amy Winehouse
when the troubled
singer died July 23
, says her family.
Spokesman Chris Goodman said in a statement 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 also said, "Results indicate that alcohol was present
but it cannot be determined as yet if it played a role in her death" at age 27.
It concluded, "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 [into her death] in October."