Toxicology tests showed there were no illegal substances in British singer Amy Winehouse's system when she died last month aged 27, her spokesman said on Tuesday.
In a statement, he added that alcohol was present, but that it could not be determined what part, if any, it played in her death.
"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.
"Results indicate that alcohol was present but it cannot be determined as yet if it played a role in her death."
It added that Winehouse's family were awaiting the outcome of an October inquest into the "Rehab" singer's death.
The Grammy-winning pop star had a history of drug and alcohol abuse, and it was widely assumed that they played a part in her death, although one report quoted family sources saying it could have been caused by sudden alcohol withdrawal.
The soul singer famed for her beehive hairstyle and erratic behaviour on and off stage was found dead at her home in north London on July 23.
Winehouse's last filmed performance was in Serbia in June, when she was jeered by the crowd as she struggled to perform her songs and stay upright. On some tunes, the audience did most of the singing.
The gig, posted on the YouTube video sharing site, prompted her management to cancel all scheduled performances and give the performer as long as it took to recover.
Winehouse shot to fame with the album "Back to Black," whose blend of jazz, soul, rock and classic pop was a global hit. It won five Grammys and made Winehouse — with her black beehive hairdo and old-fashioned sailor tattoos — one of music's most recognizable stars.
Winehouse's health often appeared fragile. In June 2008 and again in April 2010, she was taken to hospital and treated for injuries after fainting and falling at home.
Her father said she had developed the lung disease emphysema from smoking cigarettes and crack, although her spokeswoman later said Winehouse only had "early signs of what could lead to emphysema."
British singers Adele, Duffy and even American Lady Gaga have both credited Winehouse with helping pave the way for them.
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