"Recent use of heroin and the levels identified [in her autopsy] were likely to have played a role in her death," detective chief inspector Paul Fotheringham said at a hearing Thursday.
When the 25-year-old model and writer was found dead at home alone with her 11-month-old son Phaedra, police initially described her death as "non-suspicious" and a "sudden unexplained" passing. According to The Times, police found no evidence of drug paraphernalia in the house and Geldof's autopsy was inconclusive. Samples were then sent out for a toxicology screening.
Geldof's death bears a striking resemblance to that of her mother, Paula Yates, who passed away from an accidental heroin overdose in 2000 while she was home alone with her daughter and Geldof's half-sister.
The Times reports that Geldof had grown increasingly fascinated by her mother's death, with the last picture Geldof shared on Instagram being one of Yates holding the model as a child.