New Delhi: Alleged black money amounting to Rs 30 crore was seized after the Income Tax department raided a coaching institute in Tamil Nadu, training students for various competitive exams such as NEET, the CBDT said on Saturday.

It said 17 premises of the unidentified group based in Namakkal were raided on Friday and according to "preliminary" estimates, the income of the group was over Rs 150 crore.

The group was mainly into running educational institutions and coaching institutes for competitive exams and it comprised several partnership firms and a trust controlled by a close-knit group of individuals, the

Central Board of Direct Taxes (CBDT) said in a statement. The CBDT frames policies for the I-T department.

Seventeen residential premises of the group's promoters in Namakkal, Perundurai, Karur and Chennai were raided, it said.

The search was undertaken on the basis of intelligence inputs that the group was indulging in substantial tax evasion by "suppression" of fee receipts received from students, the CBDT said.

The modus operandi was to receive a part of the fees in cash and such cash receipts were invariably not entered in the regular books of accounts. Instead, the receipts were maintained in a separate set of accounts, it said.

Incriminating evidence of such suppression of receipts was found during the search in the form of accounts maintained in diaries, electronic storage devices and also in the form of huge sums of unaccounted cash, the board said.

It was found that cash was kept in bank lockers in the names of employees who acted as "benami", it added.

The board said a "significant" amount of cash was also found in a safe inside an auditorium on the main school premises.

"The unaccounted receipts are deployed for acquiring immovable properties as personal investments, which are then leased for long terms to the trust for expanding to other towns.

"It was also found that highly-priced faculty are hired and employed in the coaching institutes and they are paid outside the books," it said.

Based on preliminary findings, the undisclosed income of the group was estimated at over Rs 150 crore while unaccounted cash of Rs 30 crore was seized, the CBDT said, adding that the search was still on.