Former U.S. President Donald Trump's eldest son and daughter have refused to comply with subpoenas issued by the New York attorney general as part of an ongoing civil investigation into the family's business practices, ABC News reported.

Attorney General Letitia James' office said in the court documents filed on Monday that it is seeking testimony and documents from Trump, Donald Trump Jr. and Ivanka Trump "in connection with an investigation into the valuation of properties owned or controlled" by Trump and his company, the Trump Organization.

The subpoenas were first disclosed by the New York Times, which cited a person familiar with the matter.