"Donald J. Trump used his control over the Donald J. Trump Foundation for his personal, business and political interests in violation of federal and state law governing charities," Underwood said in the filing in state Supreme Court in Manhattan.
The filing was a memorandum opposing Trump's effort to dismiss a lawsuit Underwood filed in June against the president, his three adult children and the foundation, claiming "a pattern of persistent illegal conduct" for more than a decade.
In June, Trump took to Twitter to rip the suit.
Underwood's petition accuses the foundation of "extensive unlawful political coordination" with Trump's presidential campaign.
The Democratic attorney general said Trump used the foundation's name and funds it raised from the public to pay off his own legal debts, promote Trump hotels and other businesses, and to "purchase personal items." Among those items is a potrait of Trump purchased for $10,000, which was displayed in one of the president's hotels.
Her suit was followed a month later by a separate probe of the foundation opened by New York state tax officials.
Alan Futerfas, a lawyer for Trump and the foundation, had no immediate comment on Underwood's latest filing.
Futerfas previously has said the Trump Foundation followed the law, and said Underwood's lawsuit was politically motivated.
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