Four persons were arrested on Friday with pangolin scales from the city's Jorasanko area, police said.
Jamini Mahato, Shankar Mahato, Kashi Nath Parui and Tapan Paul were arrested after six scales of pangolin, which is an endangered species, were found with them, a senior police officer said.
A case under Wild Life Protection Act has been registered against them at the Jorasanko Police Station, he said, adding that they are being questioned for gathering more details.