The document does not say when the subpoenas were issued to the two Trump children. The former president and his son, Eric, have been asked to testify by the attorney general.
According to the New York Times, Eric Trump was interviewed in October.
Donald Trump's attorneys filed a federal lawsuit in December to block the probe and prevent him from having to testify.
The elder Trump has attacked the integrity of Attorney General Letitia James and the investigation being conducted by her office as motivated by her personal animus and political ambitions.
"Letitia James is the most unethical Attorney General this country has ever seen," said a Trump attorney. The way she has weaponized her office through this political witch hunt is against the law.
The Manhattan district attorney's office has been looking into allegations of business, insurance, bank and tax fraud, but the exact scope of James' investigation is unknown.
The attorney general's office will oppose attempts to quash its subpoenas, as they seek sworn testimony from the Trumps.
"Despite numerous attempts to delay our investigation by the Trump Organization, we are confident that our questions will be answered and the truth will be uncovered because no one is above the law," said Fabien Levy.
A previous version of the report had a spelling error.
