Attorneys for Deutsche Bank told a federal panel of judges Tuesday afternoon that the company has in its possession copies of the tax returns of at least one member of President Donald Trump's family or business entity owned by the family, but did not publicly state whose financial documents they were.

The bank indicated that it had tax documents for either the president or one of his three eldest children, who have played key roles in his business dealings.

A decision from the U.S. Court of Appeals for the Second Circuit, which is expected soon, could allow Congress to obtain those filings and other financial documents of Trump or his children.

The bank wrote in a letter to the Second Circuit that it had the tax returns of someone, or multiple people, targeted by congressional subpoenas, but redacted any identifying information.

Those subpoenas, issued earlier this year, asked Deutsche Bank and Capital One for documents related to the finances of Trump, and his three eldest children: Donald Trump Jr., Eric Trump, and Ivanka Trump.

Deutsche Bank wrote in the letter to the Second Circuit Tuesday that it had the tax returns of at least one of those individuals, and also documents related to parties not named in the subpoena who may be considered immediate family.

An attorney for Capital One wrote, in a separate letter, that the company did not possess the tax returns of any of the individuals named in the subpoenas.

The federal appellate court is currently considering whether to uphold a decision handed down earlier this year by U.S. District Judge Edgardo Ramos of the Southern District of New York, who declined to issue a preliminary injunction against the subpoenas at the time.

During arguments before the Second Circuit last week, attorneys for Deutsche Bank and Capital One refused to say whether they had copies of the president's tax returns. When pushed by the federal panel on the question, those attorneys said they were barred by contractual obligations.

Deutsche Bank is represented by Raphael Prober from Akin Gump Strauss Hauer & Feld in Washington, D.C. Capital One is represented by James Murphy from Murphy & McGonigle in Manhattan.

Both financial institutions, but Deutsche Bank in particular, have been used by Trump and his three eldest children to borrow significant amounts of money in recent years.

As part of an investigation into foreign influence on the federal government, the U.S. House Financial Services Committee and Intelligence Committee served a series of subpoenas on Deutsche Bank and Capital One earlier this year. They're seeking the financial records of Trump and his family, along with other documents.

Trump, who was represented before the Second Circuit by Patrick Strawbridge of Consovoy McCarthy, has argued that the subpoenas were served with no other purpose than to target him politically. They're asking for the subpoenas to either be thrown out or narrowed, though Ramos declined to do either in his ruling three months ago.

Instead, Ramos issued a decision from the bench affirming the power of Congress to conduct investigations, though he said the subpoenas were "undeniably broad."

"Put simply, the power of Congress to conduct investigations is inherent in the legislative process," Ramos said.

He said, during his decision, that Trump and his children were unlikely to succeed in the litigation on their arguments that Congress lacked the constitutional authority to issue the subpoenas to Deutsche Bank and Capital One.

Attorneys for Trump are asking the Second Circuit to reverse that decision, which could send the lawsuit back to Ramos for further proceedings. During a hearing last week, they argued that Congress was improperly taking on the role of law enforcement, rather than a legislative body.

During the hearing, Strawbridge called the subpoenas the "broadest possible subpoenas ever served that target a sitting president."

Douglas Letter, general counsel for the U.S. House of Representatives, argued that the subpoenas had a legitimate purpose for Congress. They were part of a broader effort to investigate money laundering and foreign influence on the U.S. government, according to Letter.

If allowed to stand, the subpoenas would allow Congress to obtain several of the president's financial documents, but it was unclear during the hearing whether that would include his tax returns, or those of his family.

When asked whether they were in possession of those tax filings, attorneys for both Deutsche Bank and Capital One said they couldn't say as much in open court.

Second Circuit Judge Peter Hall, who appeared to grow frustrated at the answer, had asked the attorneys whether they would have to seek legal intervention over the query.

"Do we have to go to court to seek an order?" Hall said. "I'm serious."

The end result was an order handed down by the Second Circuit Monday evening requiring attorneys for both financial institutions to file a letter saying whether they had copies of the president's tax filings or not.

It's not the only litigation directed at revealing the financial information of Trump, who broke decades of tradition by refusing to disclose copies of his tax returns during his run for president in 2016. Since then, Democrats have been seizing at opportunities to learn more about his finances.

The U.S. House of Representatives Oversight Committee, for one, issued a subpoena to Trump's personal accounting firm, Mazars USA, after his former personal attorney, Michael Cohen, testified before Congress that the president may have previously inflated the value of his assets to financial institutions.

That subpoena was upheld by a federal judge in Washington, D.C., and is currently under review by the U.S. Court of Appeals for the D.C. Circuit. A decision is expected soon.

New York Attorney General Letitia James has also subpoenaed Deutsche Bank and Investors Bank based on the same testimony, but there has yet to be any updates on those inquiries.

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