More than 100 experts have sounded a pre-election alarm over Indian economic data, accusing Prime Minister Narendra Modi's government of tweaking or burying unwelcoming numbers.
Modi is vulnerable over his economic record in the polls starting on April 11, in particular a failure to meet promises to create enough jobs for the million Indians entering the labour market each month.
The warning comes after India's central bank chief quit in December in a spat over alleged government interference.
His successor, a Modi ally, oversaw a economy-boosting cut in interest rates last month in his first monetary policy meeting.
The 108 economists and social scientists said in an open letter that Indian statistics were "under a cloud for being influenced and indeed even controlled by political considerations".
"Any statistics that cast an iota of doubt on the achievement of the government seem to get revised or suppressed on the basis of some questionable ideology," they said.
Economists in fellow emerging Asian giant China and abroad have long suspected that data there is also massaged.
They note that often full-year gross domestic product hits Beijing's pre-set targets with suspicious regularity.
In 2015, the Indian Central Statistics Office (CSO) revised economic output numbers for past years, changing the base year and showing significantly faster – and questionable – growth rates.
The letter also questioned a revised growth rate of 8.2% in 2016-17, "the highest in a decade!", that "seems to be at variance with the evidence marshalled by many economists".
That raised particular suspicion since it was when "demonisation" – one of Modi's biggest and most derided economic policies when 86 percent of banknotes were withdrawn – hit businesses hard.
This was followed in 2017 by the tardy rollout of a nationwide new Goods and Services Tax (GST), which has been praised by experts but which has had considerable teething problems.
The letter also noted that a major and overdue survey on employment has still not been released.
Two senior statistics officials have resigned in protest at the delay.
Press reports have said the study, the first of its kind since 2011-12, showed unemployment was at its highest since the 1970s. The government says it has not been finalised.
"The national and global reputation of India's statistical bodies is at stake. More than that, statistical integrity is crucial for generating data that would feed into economic policy-making and that would make for honest and democratic political discourse," the report said.
Signatories included Sripad Motiram at the University of Massachusetts Boston, Paul Niehaus at the University of California San Diego and Abhijit Banerjee at the Massachusetts Institute of Technology (MIT).
"Quality of data has deteriorated and governmental interference has created an atmosphere where we don't have objective assessment of India's economic growth," Ashutosh Datar, an independent economist, told AFP.
"The government's interference has created a huge problem," he added.