The BJP, which has just replaced the Congress as the party in charge of Haryana, has said Mr Vadra's real estate transactions will be investigated to determine if he was allowed sweetheart deals while the Congress was governing the state.
Mr Vadra is a fitness enthusiast who has often expounded on his workouts with accompanying photoshoots for magazines. Sources close to him say that he was attending a private event on Saturday evening - the inauguration of a gym at a Delhi hotel - and did not realise that the reporter he aggressively castigated was from news agency ANI. (It Was a Private Event: Sources Close to Robert Vadra)
Responding to Mr Vadra's outbursts, BJP leader Seshadri Chari told NDTV: "I can tell you that the Centre and the BJP government in Haryana are serious in probing all wrongdoings. I think he thinks the government is not serious." (See Other Reactions)
The Congress and Bhupinder Singh Hooda, who was the chief minister of Haryana till last month when the party lost the state election, have said that Mr Vadra's property deals were legitimate and fair.
In his campaign for the national election and then for the Haryana polls, the Prime Minister said that Mr Vadra had accrued windfall gains in Haryana because of his powerful connections. However, the Prime Minister and other BJP leaders have said that any inquiry will be free of political vendetta.