Based on an information, a group of forest and police officials, in plain clothes, posed themselves as prospective buyers and sought nails and teeth from the woman of Bokkapuram.
While negotiating, three persons, including the woman's son, all haling from villages surrounding the tiger reserve, showed them eight nails and four teeth of tiger and 17 nails and four teeth of leopard, police said.
Investigations were on to find out the source of supply and whether the arrested tribals indulged in poaching the animals, police said.