President Donald Trump dismissed allegations in a New York Times story that he had received vastly more money from his father than previously admitted - in possible violation of tax laws - as "very old" and "boring".
The New York tax department said it is studying the Times' 15,000-word report and "vigorously pursuing all appropriate avenues of investigation".
A statement from President Trump's brother, Robert, points out that Fred Trump died in June 1999 and says the Internal Revenue Service closed his estate two years later.
"Many decades ago the IRS reviewed and signed off on these transactions", White House Press Secretary Sarah Sanders said in a statement Tuesday evening.
The Times said the Trump family hid millions of dollars of transfers from the father to his children through a sham company owned by the children called All County Building Supply & Maintenance.
Trump's father saved the family hundreds of millions of dollars by undervaluing properties they gifted to their children.
The Times report noted that most, if not all, of the alleged financial crimes would have already passed the statute of limitations.
The report paints an incredibly damning picture of Trump, as it proves that his fortune was not self-made-as the president has spent a lifetime asserting-but it came directly from his father in a litany of sketchy ways.
Soon after graduating college, Trump was earning the equivalent in today's dollars of $1 million annually from his father.
For example, the Times said Fred Trump gave ownership of most of his real estate empire to his children a year and a half before his death.
The White House did not respond to the Times request for comment, but Charles Harder, one of the president's lawyers, denied the report in a statement as "false" and made a thinly veiled threat of legal action should the paper publish its report.
"The president's parents, Fred and Mary Trump, transferred well over $US1 billion in wealth to their children, which could have produced a tax bill of at least $US550 million under the 55% tax rate then imposed on gifts and inheritances".
As The New York Times exposé broke Tuesday, the New York State Department of Taxation and Finance said it has opened an investigation into the Times' allegations of fraud and tax evasion.
According to the Times, Trump's wealth was largely inherited from his parents and was increased through shady tax practices and, in some cases, "outright fraud". Needless to say, there is a reason Donald Trump did not want to release his tax returns.
Maryanne Trump Barry, Trump's sister, described her father's reaction in a deposition.
The Trump siblings allegedly undervalued their father's real estate, reporting the properties were worth a combined $41.4 million in tax returns. The implausibility of this claim would be made plain in 2004, when banks valued that same real estate at almost $900 million. The buildings were sold over the next decade for 16 times amount, according to the Times. But records show they apparently only ended up paying about $52.2 million.
When big projects went bust, Trump used his father's empire to secure loans to sustain his business.
The President's share was $177.3 million, or $236.2 million in today's dollars.