They said forest department personnel were engaged in combing operations in Kottappatti range when they spotted the gang cutting the carcass of an animal. All of them fled on hearing the officials but the team chased them and arrested the gang leader R Karunaharan.
Officials recovered the carcass of a beheaded bison and the head.
Karunaharan was later handed over to police.
The recovered carcass was buried in the Divisional Forest Office area in Harur today, officials said, adding that a search was on to nab the other gang members.