Congress chief Sonia Gandhi has dared the government to "conduct an inquiry if you have proof " over the NDTV report into whether her son-in-law, Robert Vadra bought a benami house in London by an arms dealer who was raided last month.

"They make these false allegations every day," Sonia Gandhi told NDTV. "Let them hold an inquiry... the truth will then emerge," she said, adding this is part of the government's agenda to deliver a "Congress-mukt Bharat", a phrase coined by Prime Minister Narendra Modi against the opposition party.

"Truth will come out once probe is done. Prove it. Doodh ka doodh pani ka pani ho jayega. This is a conspiracy. False allegations every other day. PM is the prime minister of the nation, not a shahenshah," she said. 

Robert Vadra, son-in-law of Congress chief Sonia Gandhi, is being probed after Income Tax raids on controversial arms dealer Sanjay Bhandari revealed alleged links between the two and cryptic references to a London property, NDTV reported on Monday.

Citing a preliminary report prepared by the Income Tax department and the Enforcement Directorate following raids last month on 18 premises owned by Bhandari, NDTV said that emails were found which were allegedly sent by Robert Vadra and his executive assistant, Manoj Arora, to London-based Sumit Chadda, a relative of Bhandari.