Mr Gray, 46, was found dead in the lounge room of his Elizabeth Bay apartment in Sydney's east on February 15.
A court has heard previously that he was found to have a "plethora" of drugs in his system, including heroin.
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Sherryn Marie Davis, 22, was charged with causing his death "in circumstances amounting to manslaughter, to wit, an unlawful and dangerous act".
She was also charged with supplying heroin to Mr Gray and stealing $3000 of his property, including a laptop, a camera and clothing.
At Sydney's Central Local Court last week, prosecutors withdrew a charge of manslaughter and a second charge of administering or attempting to administer a prohibited drug to Mr Gray.
Davis pleaded not guilty to charges of supplying Mr Gray with heroin and to a charge of larceny relating to the laptop computer.
Bail was continued and Davis will next face court on September 23.
