London police tell AP that an autopsy on Peaches Geldof, 25, who was found dead at her home in Kent, England on Monday, has been completed, but it was inconclusive.
Toxicology tests will be conducted in an attempt to determine what killed the British socialite.
Kent Police say the toxicology report could take several weeks.
Geldof, the daughter of Irish musician Bob Geldof, had worked as a model, writer and television presenter.
Police are treating her death as "non-suspicious but unexplained," reports AP.
Meanwhile, Peaches' sister, Fifi Trixibelle Geldof, posted a photo, paying tribute.
"My beautiful baby sister. ... Gone but never forgotten," Geldof, 31, wrote. "I love you Peaches."