If there was misuse of any public funds, then an inquiry is called for to find out the source of the funding as then it becomes a "serious" matter, party spokesman Abhishek Singhvi told reporters here.
He was responding when asked about questions raised in a book whether Clinton Foundation received money from Amar Singh in 2008 as quid pro quo for getting the Indo-US nuclear deal pushed.
"First and foremost, the US political scene is hotting up because of Presidential elections," Singhvi said, apparently seeking to link the issue to the polls in America.
The book 'Clinton Cash' speculated that Singh was conduit for powerful interests in India pushing for approval of the Indo-US nuclear deal, New York Post reported.
In its report, the Post said the 2008 donation by Singh was made as the US Congress debated the approval of the landmark India-US civil nuclear deal. Hillary Clinton, who was then Co-Chair of the Senate India Caucus and an eminent Senator, supported the bill, which was passed by the Congress with an overwhelming majority.