The incident is said to have occurred at about 17:15 local time (11:45 GMT) at the Basuguda camp in the Bijapur district of Chhattisgarh state.
Police said the man has been detained.
A spokesperson for the CRPF said the officer, 35-year-old Sanath Kumar, opened fire with an AK-47 assault rifle “following a scuffle with other personnel”.
Mr Kumar is being questioned and an investigation into Saturday’s incident is under way.
A senior state police officer, Sundar Raj, told ANI news agency that investigators were trying to determine “what happened, why he did it, and under what circumstances”.
The central paramilitary force is deployed in the region for anti-Maoist operations.
The mineral-rich state of Chhattisgarh has witnessed an armed conflict for more than three decades.
While the government encourages mineral extraction industries in the area, the Maoists – an armed left-wing rebel guerrilla group – opposes it.
In January, a paramilitary soldier from one of India’s elite security units killed four of his senior officers in an apparent row over leave.