The incident took place in CBT Ground in Anand Vihar and the deceased has been identified as Omvir Singh Dhama, who was posted in the Security Wing.
He had gone there to attend a wedding.
"One person was checking his revolver when it went off accidentally. The bullet pierced through the right side of Dhama's body. He was rushed to a hospital where he was declared brought dead," a senior police official said.
The man who was with the revolver has been detained.
"Prima facie, it appears to be a case of accidental firing," the official said.
New Delhi: A 53-year-old Assistant Sub Inspector was killed in accidental firing during a wedding in east Delhi, police said Saturday.
First Published: Saturday, January 19, 2013, 11:12