US President Donald Trump's businesses lost a total of more than $US1 billion ($NZ1.52b) from 1985 to 1994, according to The New York Times, which said it obtained printouts from Mr Trump's official Internal Revenue Service tax transcripts.
The newspaper said Mr Trump posted losses in excess of $250 million in both 1990 and 1991, which appeared to be more than double any other individual US taxpayer in an annual IRS sampling of high-income earners.
Mr Trump lost so much money that he was able to avoid paying income taxes for eight of the 10 years, the Times said.
Over the 10 years, Mr Trump's core businesses, including casinos, hotels and apartment buildings, lost $1.17 billion, according to the newspaper.
The White House did not immediately respond to a request for comment.
The Times quoted a lawyer for the president, Charles Harder, as saying the tax information was "highly inaccurate".
Exclusive: The New York Times has obtained a decade of Donald Trump’s tax figures. They show over $1 billion in business losses from 1985 to 1994. https://t.co/GDiZIBuJS3— The New York Times (@nytimes) May 7, 2019
Mr Trump, a real estate magnate who turned over the running of his businesses to his sons after his election in 2016, touted his business acumen and negotiating skills on the campaign trail.
Mr Trump broke with a decades-old precedent by refusing to release his tax returns as a presidential candidate in 2016 or since being elected, saying he could not do so while his taxes were being audited.
On Monday (local time), US Treasury Secretary Steven Mnuchin refused a request by the Democratic chairman of the House of Representatives Ways and Means Committee for Mr Trump's tax returns.
Democrats want Mr Trump's tax data as part of their investigations of possible conflicts of interest posed by his continued ownership of extensive business interests, even as he serves as president.