President Trump's daughter Ivanka
has been questioned under oath over claims that not-for-profit funds were misused at Mr Trump's inauguration in 2017.
A lawsuit launched by District of Columbia (DC) Attorney General Karl Racine
alleges that Mr Trump's real estate business and other entities misused the funds to enrich the Trumps.
The lawsuit alleges that a tax-exempt non-profit organisation called the 58th Presidential Inaugural Committee
worked with the Trump family to overpay for event space
at the Trump International Hotel in Washington.
In one case, the lawsuit alleges, the non-profit organisation paid more than $300,000 (£222,000)
for a private reception at the Trump International Hotel for Mr Trump's three eldest children, Donald Jnr, Ivanka and Eric
The event took place on the evening of 20 January 2017
, the day of Mr Trump's inauguration
Earlier this year, Mr Racine said: "District law requires non-profits to use their funds for their stated public purpose, not to benefit private individuals or companies."
His lawsuit is seeking to recover more than $1m in alleged improper payments made to the Trump International Hotel during the week of the inauguration.
Mr Racine's office has subpoenaed records from people including Ivanka Trump, First Lady Melania Trump and Thomas Barrack Jnr
, a friend of Mr Trump's and the chairman of the inaugural committee, according to the Washington Post newspaper.