The death occurred in the presence of a team from the Punjab vigilance bureau, which had brought IAS Sanjay Popli to his residence for an inquiry.
"After verification, they realised his son has shot himself with his licensed gun," Kuldeep Chahal, SSP Chandigarh told NDTV. Chahal claimed that it was a case of suicide and that 27-year-old Kartik Popli had shot himself.
However, Sanjay Popli's wife accused the vigilance team of murder, saying that they had "humiliated and tortured" Kartik, reported Hindustan Times. Members of the family told the media that an argument broke out between Kartik, who was a law graduate, and the vigilance team.
The body of the deceased is under the Chandigarh Police's custody, and has been sent for postmortem.
"Bhagwant Mann has killed our son. The vigilance team was here in our residence and they killed my son," his mother said.
Popli's relative, Anu Preet Kular, said that the vigilance team locked the IAS officer in a room and took Kartik to the first floor. "Vigilance team asked Sanjay Popli to sing on something lest it won't be good for his son... We were standing downstairs and after some time we heard sound of gun. Vigilance people murdered him," she told ANI.
The police, however, claimed that they had forcefully opened the door to Kartik's room on the first floor and rushed him to the Post Graduate Institute of Medical Education and Research (PGIMER), where doctors declared him brought dead, reported NDTV.
Punjab Congress president Amarinder Singh Raja Warring took to Twitter to express his shock and condemned the incident.
A senior Chandigarh police officer told NDTV that they had registered a case of suicide and had taken statements from family members who have accused the police of murder.
SANJAY POPLI ARRESTED FOR CORRUPTION, CHARGED UNDER ARMS ACT
IAS Sanjay Popli was arrested in a corruption case on 20 June in Chandigarh, where he was posted as the Director, Pensions, in the Government of Punjab.
He was arrested after contractor Sanjay Kumar complained of corruption over the state's anti-corruption helpline and posted a video as proof.
Kumar said that Popli was asking for a second instalment for a kickback in allotting a tender related to sewerage work, demanding a commission of one percent for clearing tenders for laying pipeline at Nawanshehar, Punjab.
The vigilance team also seized a large cache of cartridges from Popli's residence, registering a case under the Arms Act at the local police station.
(With inputs from ANI and NDTV.)