Constable Rakeshwar Singh Manhas, of the 210th battalion of CoBRA, an elite unit of the CRPF, went missing on Saturday after the gunfight along the border of Sukma and Bijapur districts.
The vehicles coming from these States are being checked thoroughly.
Twenty-two jawans were killed in the Maoist ambush in the inhospitable terrain of an edgy district of Bijapur, south Chhattisgarh, on Saturday.
Nag, who was being treated for his mental health problem, was not allowed to carry his service weapon AK-47. He took the rifle of another personnel inside the base camp to open fire.
The accused left the house after she raised an alarm and neighbours rushed to the spot.
The incident occurred in the forested terrain near Minpa were the forces were carrying out the search operation.
The injured personnel were shifted to a hospital here, where constable Mritunjoy of 115 battalion succumbed on Thursday, an official said.
The militants hurled the grenade on a team of CRPF personnel at Achabal area in the district around 6.50 pm, a police official said.
While the CRPF team was cordoning off a patch of jungle near Chintabegu village, Naxals triggered the blast of an improvised explosive device.
As many as nine CRPF personnel were killed and three others critically injured when Maoists blew up a mine protected vehicle at Kistaram in the strife-torn Sukma district.
The Maoists reportedly used few under-barrel grenade launchers, a sophisticated weapon used by security forces, to inflict fatal casualties on the troops by lobbing grenades in quick succession.
CRPF said that a video clip showing some youths beating its jawans was authentic and that it has started investigation.