The axe is believed to be 3,000 years old, Kudavayil Sundaravelu told reporters here.
Celt was found when a well situated in the backyard of a house of one Manikandan at Thirukkadaiyur was being desilted.
Sundaravelu said during the new stone age period, the Celt had probably been designed to serve as an attachment to wooden shafts and mainly used for felling trees, shaping wood and in agricultural purposes.
He said the Celt found at Thirukkadaiyur was 18 cm long and 5 cm broad.
It might have been carved from basaltic dike rocks, Sundaravelu said.