As a fresh controversy exploded over Minister of State for External Affairs Shashi Tharoor, Prime Minister Manmohan Singh today promised to act against him, if necessary, on the basis of evidence. <br/><br/>When asked with reference to BJP's demand for the minster's removel in the wake of the controversy around Kochi IPL team, the Prime Minister said in a press conference in Washington that he can not go by hearsay or what is appearing in media.<br/>