Indian police say they are investigating the death of Indian singer Krishna Kumar Kanath 'KK'.
According to the French news agency AFP, the police are investigating whether the singer's death was due to "unnatural" reasons.
The 53-year-old singer died of a heart attack during a live concert on Tuesday.
At 10:30 pm, KK was taken from his hotel to the hospital where doctors confirmed his death.
Arup Biswas, a West Bengal minister, had said that KK had died of a heart attack.
An autopsy on singer KK's body is scheduled for Wednesday.
Police officer Sanjay Mukherjee said that apart from questioning the hotel staff, they were also examining the CCTV footage to find out what happened to KK before he was taken to the hospital.
Born into a South Indian family in Delhi, Krishna Kumar Kanath was a versatile singer who recorded songs in Hindi, Tamil, Telugu, Canadian, Bengali, Marathi and Malayalam.
His popular songs include Eyes in the Eye, God knows and others.
Expressing grief over KK's death, Prime Minister Narendra Modi tweeted that his songs reflected different sentiments and were liked by people of all ages.
Narendra Modi said that KK will always be remembered through his songs.
In his last concert before his death, KK also sang the popular song 'Pal', the lyrics of which are as follows: We will remember this moment whether we stay or not.