Flowers from fans piled up in the street outside her north London home and her records saw a remarkable spike in sales, with her acclaimed Back to Black album seeing sales rise by 37 times.
Mark Ronson, who produced Back to Black called her death “one of the saddest days of my life”.
Police say the incident is “not yet explained,” with a post mortem slated for later this week.
The 27-year-old had recently spent time in rehab for drug and alcohol addiction and had been jeered during her come-back tour after appearing too drunk to perform in Serbia.
Her family said yesterday: “She leaves a gaping hole in our lives.”
She will be a major loss for her record label Universal, which called her “a gifted musician, artist and performer”.
Back to Black won five Grammy awards in 2006, including record of the year.