Washington (CNN) Deutsche Bank wouldn't say publicly on Tuesday whether it has President Donald Trump's tax returns. Yet the bank acknowledges the US House would see people's tax returns -- possibly even those of Trump family members -- if the bank fulfilled a subpoena related to Trump, according to a letter from the bank to a federal appeals court on Tuesday.

The bank's letter is the latest development in the House's slow march in seeking Trump's tax returns, and it brings into focus the possibility that Democrats leading the House could see the tax returns in short order if Congress wins the lawsuit.

In this case, the House seeks financial records from Deutsche Bank for Trump, his children Donald Trump Jr., Eric Trump and Ivanka Trump, immediate family members, the Trump Organization, trust and other Trump-family-controlled entities, as well as two people or entities whose names are kept under seal. Trump is challenging the subpoenas of the banks in court, so the banks haven't had to turn over documents yet. Trump lost at the trial-court level, and the subpoenas are currently being considered by a federal appeals court in New York.

"Based on Deutsche Bank's current knowledge and the results of the extensive searches that have already been conducted, the Bank has in its possession tax returns," Deutsche Bank told the court Tuesday.

The bank named for the court whose tax returns would go to the House if the subpoena is fulfilled, but those names are redacted in the public court record.

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