Congressional Democrats investigating alleged ties between President Donald Trump's political campaign and Russia are seeking information from Deutsche Bank.

In a letter Tuesday to Deutsche U.S. CEO John Cryan, five legislators ask for results from internal reviews the bank conducted on matters relating to Russia. One involves the "mirror trading" scandal for which Deutsche already has paid $630 million in fines, the other being personal accounts for Trump family members at the bank.

The letter from members of the House Financial Services Committee seeks more transparency on the trading scandal and information on "whether loans Deutsche Bank made to President Trump were guaranteed by the Russian Government, or were in any way connected to Russia."

"It is critical that you provide this Committee with the information necessary to assess the scope, findings and conclusions of your internal reviews," the letter states.

U.S.-traded shares of fell 2 percent in midday trade.

"Deutsche Bank has a reputation for not having controls that would deal with money laundering. There's a lot of information that we think is important to the way that this president has been looked at and his connections to Russia and the Kremlin," Democratic U.S. Representative Maxine Waters, one of the committee members who sent the letter, told CNBC's "Squawk Alley" on Wednesday.

Though the letter is posted on the committee's website, it does not appear to have bipartisan support, nor is it clear whether the committee could compel Deutsche to provide the information.

The group skewers Deutsche for past practices that have led to fines and embarrassing headlines. It also cites news reports using "unnamed sources" that say Deutsche is looking into whether loans to Trump or his family were guaranteed by the Russian government.

"At a time when nearly all other financial institutions refused to lend to Trump after his businesses repeatedly declared bankruptcy, Deutsche Bank continued to do so-even after the President sued the Bank and defaulted on a prior loan from the Bank — to the point where his companies now owe your institution an estimated $340 million," the letter said.

Deutsche Bank declined to comment.

The letter seeks "copies of any document, record, memo, correspondence, or other communication related to" both the mirror trading scheme and loans made to Trump and his family.