The New York Attorney General's Office has ordered former US President Donald Trump to pay a fine of $10,000 a day for his stubborn refusal to release his financial records.

Attorney General Letitia James applied to the court for the fine on Thursday.

James has been investigating potential financial crimes against Trump's real estate empire since 2019.

The Attorney General is investigating suspicions that the family holding company, the Trump Organization, artificially inflated the value of real estate when it wanted to obtain loans from banks and undervalued it in other cases in order to have to pay less taxes or insurance premiums.

In mid-February, a judge ordered Trump, his daughter Ivanka and son Donald Junior to testify under oath as part of the investigation.

He also obliged Trump to hand over tax and accounting documents from the Trump Organization to the Attorney General by the end of March.

To date, this has not happened.

Trump is violating the court order and is guilty of contempt of justice, said Attorney General James.

The court must "intervene immediately, because nobody is above the law".

A lawyer for Trump dismissed the demand for fines as "vexatious and unfounded".

In January, James said he had collected evidence of fraudulent financial practices.

"Throughout our investigation, we uncovered significant evidence suggesting that Donald J. Trump and the Trump Organization mispriced and fraudulently valued numerous assets." The assets were misrepresented to financial institutions to gain "economic benefits."

In parallel with the Attorney General's investigation, the Manhattan Attorney's Office is conducting a criminal investigation into Trump Corporation's business conduct.

In July last year, charges were brought against the Trump Organization and its longtime chief financial officer, Allen Weisselberg, for tax fraud.

Trump has been accused of dubious business and financial practices for decades.

It is still unclear how dangerous the investigations in New York Trump could be.

The 75-year-old former president has repeatedly raised a possible presidential re-election in 2024.

The right-wing populist is still held in high esteem by his supporters, and he is still the strong man in his Republican Party.