Employees of Deutsche Bank and Aon, two corporate giants, could be important witnesses. As two of Mr. Trump’s oldest allies — and some of the only mainstream companies willing to do regular business with him — they might offer investigators a rich vein of information about the Trump Organization.
There is no indication that either company is suspected of wrongdoing.
Because grand jury rules require secrecy, prosecutors have disclosed little about the focus of the inquiry and nothing about what investigative steps they have taken. But earlier this year, they suggested in court papers that they were examining possible insurance, tax and bank-related fraud in the president’s corporate dealings.
In recent weeks, Mr. Vance’s prosecutors questioned two Deutsche Bank employees about the bank’s procedures for making lending decisions, according to a person familiar with the interviews. The employees were experts in the bank’s underwriting process, not bankers who worked with the Trump Organization, the person said.
While the focus of those interviews was not on the relationship with Mr. Trump, bank officials expect Mr. Vance’s office to summon them for additional rounds of more specific questions in the near future, the person said.
Glimpses into the investigation have come in court records during the bitter and protracted legal battle over a subpoena for eight years of Mr. Trump’s personal and corporate tax returns and other financial records.
A month after Mr. Vance’s office demanded the documents from the president’s accounting firm, Mazars USA, in August 2019, Mr. Trump sued to block compliance with the subpoena. The case has twisted its way through the federal courts, with the president losing at every turn, and is now in front of the Supreme Court for the second time.
Danny Frost, a spokesman for Mr. Vance, declined to comment on recent moves in the investigation. Alan Garten, the Trump Organization’s general counsel, declined to comment, but recently said that the company’s practices complied with the law and called the investigation a “fishing expedition.”