Kapil Sibal accused PM Modi of not ordering probe to uncover "the loot" during demonetisation.
The Congress on Wednesday described demonetisation as the "biggest scam" of the country and alleged that it "may have helped criminals to monetise by looting the treasury and the poor".
Addressing a press conference in New Delhi senior Congress leader and former Union Minister Kapil Sibal accused Prime Minister Narendra Modi of "sleeping" and not ordering probe to uncover "the loot".
"Why was the 'chowkidar' asleep when all this happened? The absence of an investigation suggests that those involved in this loot are being protected. Those who have collaborated with corruption cannot pretend to be clean," said a statement issued by the Congress.
The statement said that Congress' "expose" on April 9 had spoken of alleged role of Rahul Ratharekar, a field assistant, and sought to prove his identity through his identity card, which was purportedly seen in the video. He said the "expose" also talked of involvement of a banker.
Mr Sibal said the Cabinet Secretariat issued a statement soon afterwards, saying that Ratharekar had been its constable-level employee and was dismissed in June 2017 "on suspicion of his role in exchange of old currency notes, post demonetisation".
The party said that the statement "clearly demonstrates" that the expose made by the party on the scam on March 26 and April 9 were genuine and the events seen in the video reflected the manner in which these exchanges took place.
"The involvement of government functionaries, bankers and state authorities clearly demonstrate a conspiracy to loot the treasury in a manner never seen before... Who in the chain was responsible for this loot? It requires a thorough investigation, which this government has failed to do despite knowledge of this scam," he said.
"It seems that the official machinery was actively participating in this huge scam and in the process enriching themselves," the former Minister alleged.
"It is unthinkable that crores of cash in the form of currency notes of Rs 2,000 denomination could have been available without the active collaboration of members of the treasury and those hoarding these notes for the purposes of making the exchange and earning commissions through such exchanges," the lawyer-politician said.