The directorate general of central excise intelligence (DGCEI) has booked TOPS Security Services Ltd in a case of service tax evasion. In its statement, DGCEI said search operations at the firm's 41 offices revealed it was raising invoices, including service tax payable on its customers, but was not paying the government. TOPS Security's Brig Jaisinghani said the issue was regarding unpaid dues to the extent of Rs 50 crore towards service tax, which the company cleared on December 31, 2012, along with interest.