Mr Guptara and Mr Willy soon will be produced before a court, said sources. The two people work with UBS Switzerland.
Here it can be recalled that recently the investigative agency, Central Bureau of Investigation (CBI) faced criticism following a statement issued by the Swiss Bank.
The statement had claimed that the CBI's claim on Indian names holding black money is Swiss banks was "uncorroborated."
"It wishes to make a clarification in view of unsubstantiated media reports that have been recently published about Switzerland and Swiss Banks," said the statement issued by Swiss Bank.
"There have been several speculations about the amount of wealth held by Indians in Swiss Banks...Such estimates and statistics lack of evidence and are uncorroborated," added the issued statement.