Peaches Geldof's death was caused by opiate intoxication.
The British star died on April 7 aged just 25. She was found at the home she shared with her husband Thomas Cohen and their two sons in Wrotham, Kent.
Now an inquest has ruled that heroin is to blame for her passing and that she died around 8pm the day before she was found.
A capped syringe was discovered in a box of sweets by her bed and other drugs paraphernalia including tights, spoons and resin from heroin was scattered around her body.
The inquest heard Peaches was a heroin addict and had been taking substitute drug methadone for two-and-a-half years prior to her death.
Her husband Thomas confirmed she had started taking heroin again in February this year. She had been having weekly drugs tests which she told him were all clear, but he now believes she may have been lying.
Thomas is understood to have found his wife's body after returning from a trip away with their older son Astala, two. Peaches had been at home with Phaedra, who is now almost 15 months old.
The heroin found in Peaches' home was of 61 per cent purity, while the normal street purity is around 25-30 per cent. Coroner Roger Hatch believes her tolerance had declined.
An earlier autopsy had proved inconclusive, leading to toxicology reports to be delayed.
"An investigation into who supplied the heroin to Ms Geldof-Cohen is ongoing. To date no one has been arrested or interviewed under caution in connection with this," Kent police said in a statement.
Peaches' mother Paula Yates died following a heroin overdose in 2000, when the TV presenter was 11.