U.S. District Judge Edgardo Ramos ruled at a court hearing in NY that Congress has the legal authority to demand the records, clearing the way for the banks to comply with subpoenas issued to them by two U.S. House of Representatives committees last month.
The proceeding comes amid the president's ongoing battle against congressional oversight, in which he has reportedly vowed to fight "all of the subpoenas".
A federal judge in NY on Wednesday ruled Deutsche Bank and Capital One can comply with subpoena requests made by congressional Democrats to turn over President Trump's financial and business records, despite objections from the Trump family. Several weeks later, Trump hit back with a lawsuit that seemed to profess a sense of victimhood.
Ahead of Wednesday's hearing, lawyers for two congressional committees wrote in a submission that Trump's attempts to block subpoenas were "flatly inconsistent with almost a century of Supreme Court precedent".
Capital One declined comment before the hearing.
The resistance from Trump officials has been fierce.
The subpoenas were issued by the House's Financial Services and Intelligence Committees as part of the long-promised investigation into the business dealings of Trump and his family members. Gov. Andrew Cuomo (a Democrat) supports the bills, but hasn't confirmed he will sign them.
During an hour of oral arguments, Patrick Strawbridge, the lead attorney for the president's team, said the subpoenas went beyond Congress' authority and were seeking "exposure expressly for the sake of exposure".
Deutsche Bank has always been a principal lender for Trump's real estate business and a 2017 disclosure form showed that Trump had at least US$130 million (RM543.75 million) of liabilities to the bank.
Ramos' decision is another legal rejection of Trump's stonewalling tactics meant to stymie Congressional investigations of his businesses.
The mounting probes reached a fever pitch on Wednesday when Trump convened an impromptu Rose Garden press conference, during which he lashed out at Democrats and ordered them to "get these phony investigations over with".
In March, before issuing their subpoena, Democratic lawmakers asked Capital One for documents concerning potential conflicts of interest tied to Trump's Washington hotel and other business interests since he became president in January 2017. It was the second time in three days that a judge had ruled against the Republican president in his fight with Democrats and Trump's lawyers were expected to appeal both decisions.
The president had already lost a similar case in a federal court in Washington this week, when a judge found that Trump could not block a Congress subpoena for information from a financial services firm that had done some accounting for him.
An attorney for the House Democrats, Douglas Neal Letter, said the committees have issued "a whole batch of subpoenas. having nothing to do with Trump or his family". US District Judge Edgardo Ramos, who was also appointed by Obama, is overseeing the NY case.