New York City investigators confirmed on Thursday that they will be joining the state’s probe into the Trump family’s real estate empire over claims tax evasion occurring over several decades.

The allegations against the Trump family, and Donald Trump specifically, stem from an in-depth New York Times investigation of a “vast trove of confidential tax returns and financial records” related to the Trump’s published on Tuesday.

The article claims that Trump and his father, Fred Trump, conspired to artificially lower the value of 25 apartment complexes that were then given to Donald Trump and his siblings to in order to underpay the taxes associated with real estate transfers.

Through a complex scheme of trust funds and sham corporations, buildings transferred to Fred Trump’s children were given fraudulently low valuations totaling just over $41 million. Less than a decade later, the buildings were sold by Donald Trump for over 16 times that amount.

“We are now just starting to pore through the information,” said New York City deputy mayor Dean Fuleihan.

Fuleihan has pledged the city’s cooperation with state agencies like the State Department of Taxation and Finance in their efforts to investigate the claims made by the New York Times, and uncover any evidence of wrongdoing by the Trump family.

Charles Harder, one of President Trump’s lawyers, denied any allegations of fraud and tax evasion, saying “the facts upon which the Times bases its allegations are “extremely inaccurate.”

During his 2016 presidential campaign, Trump promoted himself as a self-made billionaire, claiming he built a multi-billion dollar empire off the back of a $1 million loan he was given from his father.

Details revealed by the Times show that the reality of the Donald Trump’s financial relationship with his father differ greatly from those claims.

The president was a millionaire by the time he was eight years old, making the equivalent of $200,000 a year from his father’s businesses since the age of the three. Not long after he graduated from college, Trump’s yearly stipend had increased to $1 million a year in today’s dollars, a number that grew to $5 million by the time he was in his 40s.

White House press secretary Sarah Huckabee Sanders echoed the president’s campaign trail remarks, reiterating Trump’s claim that he only took a $1 million loan from his father that he then paid back.

In total, Trump received the equivalent of $413 million from his father’s real estate holdings.

The Times claims that Fred and Mary Trump, “Transferred well over $1 billion in wealth to their children, which could have produced a tax bill of at least $550 million under the 55 percent tax rate then imposed on gifts and inheritances.”

But by setting up sham corporations, filing improper tax deductions and concocting property devaluation schemes, the Trumps managed to reduce their tax burden to just $52.2 million, or about 5% of the net worth of the gifts.

Agencies are also investigating an alleged scheme the Trumps used to underpay the property tax on their empire.

The Times describes the scheme as involving a company created by the Trump family that existed largely on paper named All County Building Supply & Maintenance. The purpose of All County was to tack on an additional 20% or more to the price of items purchased for the family’s holdings.

According to the deputy mayor, by doing this, the Trumps were able to slash the amount they were paying in property taxes, as the city factors in the profitability of a rental property in its property taxes.

In light of these allegations, many Congressional Democrats have renewed their calls for the president to release his income tax returns. Thus far, President Trump has been reluctant to do so, and has refused the calls, breaking the 40 year long precedent set by previous administrations.