Mr Hershman, who was in New Delhi last week to attend a conference of private detectives, alleged that the bribe of the Bofors gun scandal had been parked in the Swiss account.
"The agency has learnt of the matter pertaining to the Bofors aired on certain TV channels containing interview of Michael Hershman," CBI information officer and spokesperson Abhishek Dayal said in a statement.
"Facts and circumstances as mentioned in the interview will be looked into as per due process by the CBI," he said.
Mr Hershman was quoted as telling television channels that Rajiv Gandhi got very upset when "our work was uncovered". He then formed a Supreme Court commission to look into the circumstances surrounding then finance minister VP Singh's hiring of Fairfax.
In his interviews, Mr Hershman has expressed willingness to testify and help Indian agencies on the Bofors gun pay-off scandal but the effort has to be a credible one.