Sagayam received an anonymous letter threatening to kill him and had forwarded it to the Police and District Collector.
Security for Sagayam has been increased and his office was guarded by the police already, police said.
Sagayam as the then District Collector of Madurai in 2011 has pegged loss to the state exchequer due to illegal granite quarrying at Rs 16,000 crore over several years.
Meanwhile, Madurai Rural Superintendent of Police Vijendra Bidari today met Sagayam here and briefed him about the steps taken by the Police department on the complaints against granite miners.
