"Haseena Parkar, sister of Dawood Ibrahim, died today," Additional Commissioner of Police, Krishna Prakash, told PTI.
Sources in the Mumbai police said that Parkar (55), who was commonly known as Haseena Aapa, died at the Habib Hospital in Dongri.
"After she complained of chest pain she was taken to the hospital at 2.30 pm. However, the doctors treating her declared her dead 45 minutes later. Doctors said that she died of a heart attack," another police official said.
Her body was then taken to her residence in South Mumbai.
According to police, Parkar had forayed into the underworld after the death of her husband Ismail Parkar, who had been shot dead by the Arun Gawali gang in 1991.
She had some cases of extortion registered against her, they said.