Some 2,380 people have died after being found fit for work and losing benefits, Department for Work and Pensions (DWP) figures show.
Between December 2011 and February 2014 the equivalent of about 90 people a month died after their Employment and Support Allowance claim was ended.
Campaigners have called for the "tragic" figures to be investigated.
The DWP said no link could be assumed between the deaths and claimants being deemed fit for work.
The data does not contain a breakdown of how the people died.
The 2,380 people who died had received Work Capability Assessments (WCA) to decide if they were eligible to receive ESA, which replaced incapacity benefit, income support and severe disablement allowance in 2008.
Of the 2,380, 1,340 died after appealing against their decisions, though it is not known what proportion of those appeals were successful or failed.
Learning disability charity Mencap said the numbers appeared unusually high for people of working age who had so recently been declared fit.
The charity's Rob Holland, who co-chairs the Disability Benefits Consortium, a consortium of charities and other bodies, said: "These tragic figures are concerning and warrant further investigation.
"We know the fit for work test is failing disabled people, with devastating consequences."
The figures said 2,017,070 people were given a decision following their WCA between May 2010 and February 2013, with 40,680 dying within a year of that decision.
But the data showed a decline in the mortality rate of all benefit claimants - the number of deaths per 100,000 people - from 822 to 723 between 2003 and 2013.
This was slower, proportionally, than the decline in the mortality rate of the general population, which fell from 305 to 240 in the same period, according to the statistics.
Mike Sivier, a campaigner who made one of the FOI requests, said: "I am glad that the figures have come out.
"The whole point of making an FOI request was to raise questions. It is important to keep asking questions."
Labour leadership candidate and shadow health secretary Andy Burnham said they were "shocking figures" and called for an "urgent national debate" about the statistics.
The DWP said it had always intended to release the information but only "once they had met the high standards expected of official statistics".
It said it did not hold the information on the reason for the deaths which meant no link could be drawn between the WCA decision and the number of people who died.
A DWP spokesman said: "The mortality rate for people who have died while claiming an out-of-work benefit has fallen over a 10-year period. This is in line with the mortality rate for the general working-age population.
"The government continues to support millions of people on benefits with an £80bn working-age welfare safety net in place."