The London Ambulance Service was called to her flat just after 4pm but were unable to save her life.
“On arrival, officers found the body of a 27-year-old female who was pronounced dead at the scene,” a police statement said. Her death is being treated as unexplained and inquiries are continuing into the circumstances, it added.
The Back To Black artist had cancelled all tour dates and engagements last month after a series of erratic public appearances. She had been troubled by drink and drugs problems throughout her career.