The Income Tax Department will soon issue notices to those who have deposited “suspicious” amounts of money in banks post-demonetisation and have not responded to taxman’s preliminary communication, the CBDT said on Tuesday. Sushil Chandra, Chairman, CBDT said despite closing of I-T returns filing time period, a number of entities and individuals failed to file their tax returns, as required under the ‘Operation Clean Money’ (OCM) initiated by the Government to check black money post demonetisation.