Constable Ranjit Singh, who was attached as security guard with revenue minister Ajit Singh Kohar, was killed after his carbine went off accidentally at Kohar Kalan village on Wednesday night.
A resident of Muktsar Sahib, he belonged to the 75th battalion of the Punjab Armed Police (PAP).
Shahkot DSP MS Bhullar said a bullet hit Ranjit Singh, who died on the spot, and two bullets hit the ceiling. He claimed that it was an accident.
Investigating officer assistant sub-inspector (ASI) Charanjit Singh said a case under Section 174 of the CrPC had been registered on the statement of escort in charge ASI Seetal Singh.
He said the incident took place when Ranjit Singh was unloading his weapon in the guardroom after duty hours.
The body was handed over to the family after a post-mortem was conducted at the civil hospital.