Sources said the drive has been undertaken by the department under instructions from its apex policy making body -- the Central Board of Direct Taxes -- which desires that the taxman should "examine all cases related to foreign assets" as a number of these will get time-barred by this month end.
The CBDT, in 2012-13, had introduced a new column in the Income Tax Return (ITR) forms which made it mandatory for individuals and other entities to disclose their foreign assets for the purpose of tax assessment.
"A number of cases will get time barred by March 31 this year. This means that the I-T department will not be able to take action in cases pertaining to 2007-08 assessment year where foreign assets or bank accounts are present and have been disclosed.
"Under the current crack down on black money, instructions have been issued to field offices to undertake a close scrutiny of such cases where the taxpayers have disclosed such assets themselves or I-T investigations or intelligence have indicated presence of such assets in the name of an individual or entity," a senior Finance Ministry official said.
The taxman has also been asked to obtain from the assessee information about the source of funds used for creating the particular asset or bank account in the foreign land and connected reasons thereof, the official said.
CBDT has also asked tax officials to collect all such information and send it across to its Foreign Tax and Tax Research (FT and TR) unit so that any possible cooperation on such cases can be sought from foreign countries "well in time".
The latest measures to combat black money, the official said, have made it essential for I-T authorities to obtain any possible assistance from partner countries about any individual or entity holding illegal foreign asset or such property which the department feels is not disclosed to it fully.
"The existing tax information exchange treaties like Double Taxation Avoidance Agreement (DTAA), Tax Information Exchange Agreements (TIEAs) and other bilateral treaties on tax would be activated if the field formations of the I-T department report anything with regard to foreign assets, whether movable or immovable," the official added.
Officials said the I-T department will verify all such cases as there have been instances of connected or layered holdings of assets by entities or individuals while creation of shell companies have also been reported in the past.
"The exercise is just to ensure that the I-T department knows every financial information about an assessee who holds a foreign asset, whether declared or undeclared," the official said.