A preliminary post-mortem report has suggested that singer Krishnakumar Kunnath, popularly known as KK, died due to a cardiac arrest, PTI reported on Wednesday.

“There was no foul play behind his death,” an unidentified senior officer of the Kolkata Police said. “Clinical examination also found that the singer was having prolonged cardiac issues.”

The officer also said that a final post-mortem report will be available after 72 hours.

KK died on Tuesday night shortly after performing at a concert at the city’s Nazrul Mancha auditorium. He collapsed at the hotel where he was staying after the performance. Doctors at the Calcutta Medical Research Institute said that the singer had died by the time he was brought to the hospital.

Doctors had said he possibly died due to cardiac arrest, but police had filed a case of unnatural death on Wednesday and conducted a post-mortem to identify the exact cause.

This was after initial investigation showed he was “almost mobbed” by fans at the hotel where he returned after the performance.

“The singer had allowed a couple of fan followers to take photos with him, but then he refused to carry on with the selfie session,” a police official had said on Wednesday. “He left the lobby and then went upstairs where he had reportedly stumbled and fallen on the floor. People who were with him informed the hotel authorities.”

KK reportedly sustained two injuries – one on the left side of his forehead and another on his lips – possibly due to the fall.

Videos shared on social media showed that KK was visibly in discomfort during the concert. In one of the videos, he was seen wiping sweat and apparently gesturing that the air conditioning at the venue was not working. A person was heard saying it was extremely hot there.

Another video showed KK saying “God bless you all” to the crowd before leaving the stage in a hurry. He was visibly distressed as he was taken away from the venue.

A third video showed the exhausted singer being taken back to his hotel after the concert.

On Wednesday, a doctor, who conducted the autopsy of KK’s body, said that the singer’s heart had several blockages and he could have been saved if cardiopulmonary resuscitation, or CPR, was administered on time.

A CPR is an emergency procedure comprising chest compressions as well as artificial ventilation to manually maintain brain function until further steps are taken to restore normal blood circulation and breathing in a person experiencing cardiac arrest, according to PTI.

“The vocalist had 80% blockage in the left main coronary artery and small blockages in various other arteries and sub-arteries,” the doctor told PTI on conditions of anonymity. “During Tuesday’s performance, the singer was walking around and at times dancing with the crowd which created excessive excitement that caused the stoppage of blood flow leading to cardiac arrest.”

Meanwhile, KK’s body was taken to the Rabindra Sadan in Kolkata where he was accorded a gun salute. West Bengal Chief Minister Mamata Banerjee and his family members were present.

The singer’s body was then flown to Mumbai and was later taken to the Versova cremation ground for the last rites on Thursday afternoon, according to ANI.