Donald Trump's business losses in 1995 were so large they could have allowed him to avoid paying income taxes for as many as 18 years, according to records obtained by The New York Times.
The newspaper said it anonymously received the first pages of Mr Trump's 1995 state income tax filings in New York, New Jersey and Connecticut.
They show a net loss of 915,729,293 dollars in federal taxable income for the year.
That Mr Trump was losing money during the early to mid-1990s - a period marked by bankruptcies and poor business decisions - was already well established.
But the records obtained by the New York Times show losses of such a magnitude that they potentially allowed him to avoid paying taxes for years, possibly until the end of the last decade.
Mr Trump's campaign lashed out at the newspaper for publishing the records and accused the newspaper of working to benefit the Republican nominee's presidential rival, Democrat Hillary Clinton.
"The New York Times, like establishment media in general, is an extension of the Clinton campaign, the Democratic Party and their global special interests," the campaign said.
It called Mr Trump "a highly skilled businessman who has a fiduciary responsibility to his business, his family and his employees to pay no more tax than legally required".
The campaign said Mr Trump had paid "hundreds of millions" of dollars in other kinds of taxes over the years.
Mrs Clinton's campaign manager, Robby Mook said "this bombshell report reveals the colossal nature of Donald Trump's past business failures and just how long he may have avoided paying any federal income taxes whatsoever".
He said the report shows Mr Trump lost nearly a billion dollars, "stiffed small businesses, laid off workers, and walked away from hardworking communities".
Since 1976, every major party presidential nominee has released tax returns. Mrs Clinton has published nearly 40 years' worth, and Mr Trump's running mate, Indiana Governor Mike Pence, has released 10 years of his tax returns.
But after initially saying he would make his returns public during his campaign, Mr Trump switched course, citing what he said were years of ongoing Internal Revenue Service audits and the advice of his lawyers to keep them private.
Former IRS officials have expressed scepticism that anyone would be audited so frequently, and they and other tax experts say there is no prohibition on Mr Trump releasing his returns even if he is.
Mr Trump's campaign did not directly address the authenticity of the excerpts from his tax filings.
Former Trump accountant Jack Mitnick, whose name appears as the tycoon's tax preparer of the filings, confirmed their authenticity, telling the newspaper: "This is legit."
There are provisions in the tax code that allow wealthy individuals to offset their personal income with losses in various partnerships and business ventures.
It means Mr Trump could have used his losses in 1995 to avoid incurring tax liabilities on as many as three years of prior and 15 years of future profits.
The losses reported by the New York Times would not include previous years of losses incurred by Mr Trump while his New Jersey casino empire slid into bankruptcy.
Mr Mitnick told the newspaper he had sometimes found it odd that the tax code allowed Mr Trump to live in such luxury without paying income taxes.
"Here the guy was building incredible net worth and not paying tax on it," he said.