New Delhi: The Congress on Tuesday alleged that two different kind of notes of Rs 500 and Rs 2,000 notes were printed post-demonetisation.
The Opposition said this has "jeopardised the credibility of the Indian currency" and demanded that Prime Minister Narendra Modi come clear on it.
The Congress, which disrupted proceedings in the Rajya Sabha over the issue forcing an adjournment, said the high denomination notes were different in size, design and other features.
They also demanded that the government explain where and how they were printed as the issue "raises questions over financial structure of the country".
Senior Congress leader and former Union minister Kapil Sibal, who raised the issue in the Rajya Sabha earlier in the day, said the party would keep flagging it in Parliament until the government comes out with an explanation.
Sibal also alleged that the demonetisation move "failed" to achieve its stated objectives of combating black money, corruption, counterfeit currency and terrorism.
He demanded that the government explain the motive behind invalidating the old Rs 1,000 and Rs 500 currency notes.
"First they should explain which dye was used (for printing the notes), what types of notes were printed, at which printing press notes of different sizes were printed.
"Having different size of currency notes jeopardises the credibility of the currency. The prime minister, finance minister, RBI governor should come to the fore and explain," Sibal told reporters.
Earlier in the day, the Congress, TMC and JD(U) forced four adjournments of the proceedings in the upper House over what they termed as "biggest scam of this century" in the printing of two different kinds of Rs 500 and Rs 1000 notes.
(with PTI inputs)