New Delhi, Aug 31 (IANS): The Income Tax Department on Wednesday said they recently carried out a search and seizure operation on two prominent real estate groups of Kolkata, and have detected a total unaccounted income of more than Rs 250 crore.

The official said that during the course of the search operation on August 18, a large number of incriminating evidence, including documents and digital data, were seized.

"There are evidences of out of books cash transactions and on-money receipts. Several documents and electronic data indicate routing of unaccounted money through shell companies. Further, some of the evidences found during the search operation indicate use of unaccounted funds in land acquisition," said the official.

The official said that the key persons admitted use of shell companies for infusion of unaccounted funds in the form of share capital, share premium and unsecured loans through sale of bogus investments.

During the course of search proceedings, 16 bank lockers have been found which have been placed under restraint.