Kolkata, Aug 5: The Special Task Force (STF) of West Bengal Police was conducting marathon raids and search operations on the residences of two brothers-in-law of Tulu Mondal a.k.a. Mohammad Nazibuddin, the absconding stone quarry owner from Birbhum district of West Bengal. Thereafter, the police sealed the residence of Tulu at Suri in Birbhum district. The Enforcement Directorate (ED) has also commenced a preparatory process to probe Tulu Mondal. The central agency officials are currently collecting information from the Birbhum district police in the matter.