The court documents contain the attorney general’s most detailed accounting yet of a long-running investigation into allegations that Trump’s company exaggerated the value of its holdings to impress lenders or misstated what land was worth to slash its tax burden.

The Trump Organisation, James’ office said, overstated the value of land donations made in New York and California on paperwork submitted to the IRS to justify several million dollars in tax deductions.

When giving estimates of Trump’s wealth, the company misreported the size of his Manhattan penthouse, saying it was nearly three times its actual size – a difference in value of about US$200 million, James’ office said, citing deposition testimony from Trump’s long-time financial chief Allen Weisselberg, who was charged last year with tax fraud in a parallel criminal investigation.

James’ office detailed its findings in a court motion seeking to force Trump, his daughter Ivanka Trump and his son Donald Trump Jnr to comply with subpoenas seeking their testimony.

Investigators, the court papers said, have “developed significant additional evidence indicating that the Trump Organisation used fraudulent or misleading asset valuations to obtain a host of economic benefits, including loans, insurance coverage, and tax deductions”.

Donald Trump sues New York attorney general Letitia James

In its statement, the Trump Organisation said “the only one misleading the public is Letitia James”.

“She defrauded New Yorkers by basing her entire candidacy on a promise to get Trump at all costs without having seen a shred of evidence and in violation of every conceivable ethical rule,” they wrote. “Three years later she is now faced with the stark reality that she has no case.”

Donald Trump Jnr said on Twitter that the investigation “is nothing more than political retribution from her on behalf of the entire Dem Party. She should be disbarred!”

The disclosure comes as Trump has been laying the groundwork for a potential comeback campaign for president in 2024. He held his first rally of the new year last weekend in Arizona, where he slammed the “monsters that are using law enforcement for political retribution at the local, state and federal level” and aired an anti-James video that highlighted her past anti-Trump statements.

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Former Trump Plaza casino demolished after falling into disrepair

Former Trump Plaza casino demolished after falling into disrepair

Trump’s legal team has sought to block the subpoenas, and it asked a federal court last month to put an end to James’ investigation. That lawsuit is pending. His lawyers say James is improperly attempting to obtain testimony in her civil probe that could be used in a parallel criminal investigation overseen by Manhattan District Attorney Alvin Bragg.

In a statement late on Tuesday, James’ office said the evidence gathered so far shows that her investigation should proceed unimpeded.

“For more than two years, the Trump Organisation has used delay tactics and litigation in an attempt to thwart a legitimate investigation into its financial dealings,” James said.

“Thus far in our investigation, we have uncovered significant evidence that suggests Donald J. Trump and the Trump Organisation falsely and fraudulently valued multiple assets and misrepresented those values to financial institutions for economic benefit.”

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Although James’ investigation is separate from the criminal investigation, her office has been involved in both, dispatching several lawyers to work side by side with prosecutors from the Manhattan DA’s office.

James’ office said that under state law, it can seek “a broad range of remedies” against companies found to have committed commercial fraud, including revoking licences to conduct business in the state, seeking the removal of company officers or seeking restitution and “disgorgement of ill-gotten gains”.

In the court papers, James’ office said evidence shows that Trump’s company:

• Listed his Seven Springs estate north of New York as being worth US$291 million, based on a dubious assumption that it could reap US$161 million from building nine luxury homes

• Added a “brand premium” of 15 per cent to 30 per cent to the value of some properties because they carried the Trump name, despite financial statements explicitly stating they did not incorporate brand value

• Inflated the value of a suburban New York golf club by millions of dollars by counting fees for memberships that were not sold or were never paid

• Valued a Park Avenue condominium tower at US$350 million, based on proceeds it could reap from unsold units, even though many of those flats were likely to sell for less because they were covered by rent stabilisation laws

• Valued a flat being rented to Ivanka Trump at as high as US$25 million, even though she had an option to buy it for US$8.5 million

• Said in documents that its stake in an office building, 40 Wall Street, was worth US$525 million to US$602 million – two to three times the estimate made by appraisers working for the lender Capital One

One judge previously sided with James on an earlier request to question another Trump son, Trump Organisation executive Eric Trump, who ultimately sat for a deposition but declined to answer some questions.

Last year, the Manhattan district attorney brought tax fraud charges against the Trump Organisation and Weisselberg, its long-time chief financial officer.

Weisselberg pleaded not guilty to charges alleging he and the company evaded taxes on fringe benefits paid to executives.

The disclosures about the attorney general’s investigation came the same day as Trump ally Rudy Giuliani and other members of the legal team that sought to overturn the results of the 2020 presidential election were subpoenaed by a House committee investigating the US Capitol insurrection.