Peaches Geldof was having weekly drugs tests which she had told her husband were negative but he became concerned that she might be, an inquest was told.
North West Kent Coroner Roger Hatch said Ms Geldof had been finding it difficult to come off methadone, although she was reducing the dosage because she did not want to take it any more.
ITV News Correspondent Nina Nannar reports:
Messages found on phone made Peaches husband suspicious she was on heroin again though months before she seemed to have beaten addiction
More top news
Which of the Conservative and Labour parties is most likely to split over Brexit?
Chinese President Xi Jinping has reasserted Beijing’s willingness to use force to bring Taiwan under Chinese control.
Plans for a multibillion-pound new nuclear power station have been suspended, delivering a huge blow to the industry.