The Central Board of Direct Taxes on Monday said it is investigating as many as nine lakh cases of big money transactions, warning black money holders that it will "confront" them with this data. The move is meant to encourage defaulters to declare their undisclosed income within the compliance window stipulated by the government under the Income Declaration Scheme, PTI reported.

CBDT Chairman Atulesh Jindal said, "We have prepared a database of nine lakh pieces of information [on cases of high-value and potential unreported cases]...We will issue them [taxpayers] letters and confront them with the information we have." He also urged defaulters to avail the IDS and "come clean".

Of these nine lakh cases, more than a lakh of them deal with transactions of more than Rs 1 crore. The CBDT chief reiterated that the IDS was a "one-time opportunity" for black money holders and that the Income Tax Departmen, which reports to him, was "very serious" about tackling tax evasion.

The government recently extended the deadline, now allowing defaulters time till September 30, 2016, to pay taxes and penalties under the IDS in three installments. It also clarified that black money holders who declare their undisclosed income within the compliance window cannot pay their taxes and penalties from these sources of income. Jaitley had assured defaulters of immunity from any scrutiny, inquiry, or prosecution under the Income Tax Act or the Wealth Tax Act if they declare, if they comply with the deadline.