Jeremy Corbyn has released his tax returns to the public, revealing a total income for 2015-16 of £114,342 ($141,000).
But critics claim that the figures do not show his complete earnings as they seem to omit the salary he would have received for being party leader.
Sky News calculated that the figures are short by £40,000 - the money Corbyn earned as leader from September 2015, when he took the job, to the end of the tax year in April 2016.
The returns were released on Corbyn's website under a short statement which read: "I am publishing the detail of my tax return here on my constituency website.
"I have made it clear that I think it is right for party leaders to be open and transparent about their tax arrangements."
According to the figures, he paid £35,298 in tax. But Sky said that his total stated income of £114,342 should be closer to £150,000.
A Corbyn aide told the Guardian that though the returns looked like something was not quite right, the tax paid was correct as it was deducted at source.
The returns show that Corbyn made £77,019 from employment, £1,200 from self-employment, £78 from interest from banks and building societies and £36,045 from UK pensions and state benefits.
Labour said that the returns were prepared by a team of accountants who had been given all the information."
The release of the tax statement came after Chancellor Philip Hammond rejected pressure from shadow chancellor John McDonnell to release his own tax return.
Hammond told the BBC: "Demonstration politics isn't helping the atmosphere in British politics.
"Just for the record my tax affairs are all perfectly regular and up to date."