NEW YORK (REUTERS) - The accounting firm that handled Mr Donald Trump's company's financial statements has dropped it as a client and says it can no longer stand behind a decade of statements, a court filing showed on Monday (Feb 14).

Mazars USA, in a Feb 9 letter made public on Monday, told the Trump Organisation, the former president's New York-based real estate business, that its financial statements for 2011 till 2020 should no longer be relied on.

The disclosure was made as part of New York Attorney-General Letitia James' civil investigation into the Trump Organisation, which could result in financial penalties.

That probe partially overlaps a criminal investigation by the Manhattan District Attorney, which Ms James joined in May, into the company's practices.

Mazars said it had based its conclusion on a January filing by the New York Attorney-General and its own investigation, as well as information from internal and external sources.

"While we have not concluded that the various financial statements, as a whole, contain material discrepancies, based upon the totality of the circumstances, we believe our advice to you to no longer rely upon those financial statements is appropriate," Mazars said in the letter addressed to the chief legal officer at the Trump Organisation, Mr Alan Garten.

In the letter, filed in New York state court, Mazars said that it had "performed its work in accordance with professional standards".

The accounting firm also said it would no longer work for the Trump Organisation.

New York state's attorney-general has accused the Trump Organisation of repeatedly misrepresenting the value of its assets to obtain financial benefits.

A Trump Organisation spokesman said in a statement the company is "disappointed that Mazars has chosen to part ways".

But the spokesman added that the letter confirms that "Mazars' work was performed in accordance with all applicable accounting standards and principles" and that the statements of financial condition "do not contain any material discrepancies".

The New York Attorney-General's Office filed the Mazars letter in support of its efforts to compel the production of outstanding documents from Mr Trump and his company as well as testimony by him and two of his adult children, Mr Donald Trump Jr and Ms Ivanka Trump.

In a memorandum also filed on Monday, Ms James noted media reports that Mr Trump had destroyed documents covered by the Presidential Records Act and wants him to supply a sworn statement on whether the files produced for her probe are complete and how they may have been destroyed and by whom.

Mr Trump has decried the probe as political.

In Monday's filing, Ms James' office said the accounting firm's statement and actions further supported the legitimacy of the investigation.

Ms James has been investigating whether the Trumps inflated real estate values to obtain bank loans, and reduced values to lower tax bills.

In one example, she said Mr Trump's annual financial statements said an apartment he personally owned in Trump Tower was 30,000 sq ft when it was, in fact, a third that size.

Neither Mr Trump nor his children have been accused of criminal wrongdoing.