DVAC officials said documents in the office were being verified to cross-check the area for which actual mining permission was given and if there were any violations.
They had collected various documents including licences issued, officials said.
The raids come a day after the arrest of three officials of the state-owned Tamil Nadu Minerals LTD (TAMIN) for allegedly colluding with granite companies and allowing them to commit violations.
The crackdown on the granite firms was launched against the backdrop of a recent report by former District Collector U Sagayam pegging loss due to illegal quarrying of the blue metal in the region at over Rs 16,000 crore.
Several persons, including Durai Dayanidhi, son of Union Minister M K Alagiri, have been booked for alleged illegal sand and granite mining by companies owned by them.
