Deutsche Bank, which was hit in January with $630 million in penalties over an alleged Russian money-laundering scheme, is in the crosshairs of Democrats looking into the bank's ties to President Trump.

The lawmakers want the German bank, which has made loans to Trump's businesses, to release any internal reviews it may have conducted into loans to Trump and his family members and tied to allegations Deutsche helped wealthy Russians launder billions of dollars.

"It is critical that you provide this committee with the information necessary to assess the scope, findings and conclusions of your internal reviews," five lawmakers wrote in a letter to Deutsche CEO John Cryan on Wednesday.

Related: Deutsche Bank fined for $10 billion Russian money-laundering scheme

In January, Deutsche was fined $629 million by New York and U.K. authorities for failing to catch a group of traders from secretly transferring more than $10 billion out of the country by converting rubles into dollars.

In their letter, Democrats said the settlement left open questions as to who may have been involved in the trading scheme, where the money was sent, and who may have benefited from the sums of money transferred out of Russia.

A spokeswoman for Deutsche Bank declined to comment on the matter.

The U.S. Justice Department is conducting a separate criminal investigation into the so-called mirror trades.

The letter, sent by members of the House Financial Services Committee led by Maxine Waters, also pressed the German bank to disclose any reportedly internal reviews of whether loans made to Trump and members of his family were backed by guarantees from the Russian government or were in any way connected to Russia as they were made in "highly unusual circumstances."

While other financial firms have been reluctant to work with Trump, Deutsche has been a steadfast financial backer of the former real estate mogul's business interests.

Related: Mnuchin punts on commitment to disclose Trump's business ties

Wednesday's letter follows a previous Democratic inquiry in March to Jeb Hensarling, the chairman of the Financial Services committee, to use its oversight authority to open an investigation into Deutsche's Russian money laundering operations. A spokeswoman for the committee said that request went unanswered. A spokeswoman for Hensarling did not immediately respond to a call seeking comment.

The latest request by Democrats follows a string of demands by other party leaders, including Senator Mark Warner, the vice chairman of the Senate Intelligence Committee. Last month, Warner asked for documents from the Treasury Department's division on terrorism and financial intelligence on any probe into Russian meddling in the U.S. election.