The New York Times alleges that Donald Trump paid just $750 (£587) in federal income tax in 2016, the year he won the US presidency.
The newspaper – which says it has obtained tax records for Mr Trump and his companies over two decades – also says he paid no income taxes at all in 10 of the last 15 years.
It says this is “largely” due to the companies reporting losses.
Mr Trump dismissed the report as “totally fake news”.
“Actually I paid, but you’ll see then as soon as my tax returns are done,” he told reporters after the story was published on Sunday.
The New York Times said it had reviewed tax returns relating to President Trump and the companies owned by the Trump Organization going back to the 1990s, as well as his personal returns for 2016 and 2017.
The publication claims that Mr Trump paid just $750 in income taxes in 2016, and $750 in 2017.
The Trump Organization also rejected the allegations.
Alan Garten, chief legal officer of the Trump Organization, said that “most, if not all, of the facts appear to be inaccurate”, in response to a letter compiling the Times’ findings.
“Over the past decade, President Trump has paid tens of millions of dollars in personal taxes to the federal government, including paying millions in personal taxes since announcing his candidacy in 2015,” said Mr Garten.
In a public filing in 2018, President Trump said that he had made at least $434.9m in revenues. The newspaper disputes this, alleging that his tax returns show the president had instead gone into the red, with $47.4m in losses.
The newspaper also claims that “most” of President Trump’s biggest businesses – such as his golf courses and hotels – “report losing millions, if not tens of millions, of dollars year after year”.
The New York Times claims that the president is personally responsible for more than $300m in loans, which will come due in the next four years.
It also alleges that some of President Trump’s businesses have received money from “lobbyists, foreign officials and others seeking face time, access or favour” from the president.