Desperate to curb the flow of blackmoney into the country's economy, the Income Tax department has now begun to track all fliers and visitors who travel to tax havens like Switzerland, Virgin Islands and Bahamas for personal or business purposes secretly.

The department has focussed its intelligence and investigation scanner on all such travellers who have visited tax haven nations last year and have not disclosed the expenditure and instances of such tours in their Income Tax returns.

The drive by the I-T department assumes importance in the backdrop of the clamour to unearth blackmoney which is suspected to be stashed away essentially in such nations with taxpayer friendly laws -- called tax havens -- thereby encouraging people to hide their ill-gotten wealth in secret lockers of these countries.

The Air Intelligence Unit (AIU) of the department has liaised with the civil aviation authorities to obtain the travel details of all such travellers from various airports of the country and other locations.

The department has subsequently fed this information in its exhaustive computer-based anti-tax evasion database of taxpayers which has been developed by the Centre for Development of Advanced Computing (C-DAC).

In the initial step of the larger operation to check tax evasion, the I-T department has tracked about a thousand such individuals who had travelled extensively to these destinations in about 20 lakh air trips.

The department, according to sources, has found that a number of such travellers' details do not match with their declared intentions to visit these nations.

"Such trips could have been made by certain individuals to strike business deals here for routing and stashing blackmoney. Assessees who have not explained such instances will be asked to furnish information to the department," a senior I-T department official said.

I-T sleuths suspect some fliers could also be fronts for some individuals who themselves did not want to get into the limelight as then they would have to reflect such trips and their expenditure in their I-T returns.