Ms James sued Trump, Donald Trump Jr, Eric Trump and Ivanka Trump in September last year alleging they committed "incredible" fraud at the Trump Organization.
was back in New York on Thursday to answer questions in a civil case accusing the ex-president and three of his children of business fraud.
The behind-closed-doors deposition comes a week after Trump's historic arraignment on criminal charges in a Manhattan courtroom in a separate case.
The 76-year-old Republican was to be questioned under oath in the lawsuit brought by New York state attorney general Letitia James.
Trump pumped his fist as he left Trump Tower on Fifth Avenue shortly after 9:30 am (1330 GMT), arriving at James's office in lower Manhattan around 10:00 am.
"This civil case is ridiculous, just like all of the other Election Interference cases being brought against me," he wrote on his social media site Truth Social.
Ms James sued Trump, Donald Trump
Jr, Eric Trump and Ivanka Trump in September last year alleging they committed "incredible" fraud at the Trump Organization.
Her lawsuit asserts that they lied to tax collectors, lenders and insurers for years in a scheme that routinely misstated the value of the organization's properties to enrich themselves.
James said they provided fraudulent statements of Trump's net worth and false asset valuations "to obtain and satisfy loans, get insurance benefits, and pay lower taxes."
Trump, the frontrunner for the Republican nomination in next year's presidential election, has used his common refrain of "witch hunt" to describe the case.
He appeared for six hours of questioning in the probe last August, shortly before Ms James filed her lawsuit.
In a dramatic court appearance last Tuesday that transfixed the nation, Trump denied 34 felony counts related to hush money paid to porn star Stormy Daniels shortly before the 2016 election that brought him to power.
He became the first former or sitting president to ever be charged with a crime.
That case has been criticized almost unanimously by Republican officials, including congressional leaders who have asked Manhattan's District Attorney Alvin Bragg, a Democrat, to testify about the probe before Congress.
James, also an elected Democrat, has requested that Trump pay at least $250 million in penalties -- a sum she says he made from the alleged fraud -- and that his family be banned from running businesses in the state.
No criminal charges can stem from her case, which is expected to go to trial later this year.
Trump faces a slew of state, federal, and congressional probes that threaten to complicate his bid to regain the presidency.
They include his efforts to overturn his 2020 election loss in the state of Georgia, his alleged mishandling of classified documents taken from the White House and his involvement in the storming of the US Capitol on January 6, 2021.
A civil trial for a sexual assault and defamation lawsuit brought by former magazine columnist E. Jean Carroll against Trump is scheduled to start in New York later this month.