New Delhi: Narendra Modi's " jumla" is getting juicier and juicier, if not trickier and trickier.

The Centre on Tuesday told Parliament that estimates on black money Indians are said to have stashed abroad - an issue the BJP had played up ahead of the elections in 2014 - were not based on any verifiable data.

"There are no official estimates of black money stashed by Indians in foreign countries," finance minister Piyush Goyal said in a written reply to a question from Congress leader K.V.P. Ramachandra Rao in the Rajya Sabha.

The admission begs the question that on what basis did would-be Prime Minister Modi conclude before the 2014 election that if all the black money stashed abroad was brought back, each poor Indian could get Rs 15-20 lakh "just like that".

Hounded by questions about when the Rs 15 lakh would be deposited, BJP president Amit Shah had later described it as " jumla", which means a figure of speech but now considered synonymous with gimmickry.

On Tuesday, however, Goyal said there was "no verifiable data... available anywhere in the country" on how much black money had been unearthed since the Modi government assumed charge.

The minister said the government had commissioned a study on estimation of unaccounted income and wealth both inside and outside the country, conducted by the National Institute of Public Finance and Policy, National Council of Applied Economic Research and the National Institute of Financial Management.

The study reports have been placed before the parliamentary standing committee on finance, which is now seized of the matter, Goyal added.

Congress leader Anand Sharma asked Goyal if the special investigation team (SIT) the government had set up had gathered any information on black money. "The minister has referred to the SIT that was constituted in May 2014.... It is investigating into cases involving substantial black money/undisclosed income, particularly black money. Now, we would like to know what information is available with the SIT," Sharma asked in a supplementary question.

Goyal said: "As regards his question about the amount of black money, all such estimates in the past or even presently available are ultimately estimates drawn on different formulations.... We have left it to the parliamentary standing committee to guide us in the matter; but the explosive data that he is talking about, there is no verifiable data that is available anywhere in the country and, as I said earlier, if it was available, government would have cracked down on anybody who had that kind of money."

The minister said the government had an agreement on automatic sharing of information with several countries, and Switzerland's Supreme Court had recently ordered the Swiss government to share data on black money with India.

"In about a week or ten days that is going to get formalised," Goyal said.