The Federal Reserve Bank of New York found several deficiencies in the way German lender Deutsche Bank AG’s (NYSE:DB) U.S. unit was reporting its financial data, which, according to a Wall Street Journal report Tuesday, the company had known for years but failed to act upon.

In a letter written to the bank on Dec. 11, 2013, and cited by the Journal, the New York Fed stated that regulatory reports provided by the bank’s U.S. divisions were of “low quality, inaccurate and unreliable,” adding that despite the “size and breadth” of the errors and the Fed's instruction to overhaul the firm’s entire U.S. regulatory reporting structure, “no progress was made in remediating prior supervisory concerns.”

The letter said that the banking giant's regulatory reporting process in the U.S. was fragmented, and suffered from weak and inadequate internal controls. The Fed also added that the shortcomings in the bank, which were the result of a “systemic breakdown,” were further compounded by a lack of adequate auditing and oversight, and “longstanding weaknesses” in the firm’s information-technology infrastructure. 

The New York Fed, which has regulatory powers over banks in the U.S. and can restrict their activities, stated in the letter that, since 2002, when it first voiced its concerns over Deutsche Bank’s regulatory reporting framework, “the firm failed to produce sustainable solutions to addressing the weakness in the regulatory reporting process or to improve the quality of data.”

According to the Journal, even before the letter was written in December, Fed officials had described the bank's reporting as “the worst among its peers.”

Fed officials had also expressed concern regarding the operations of Deutsche Bank Trust Company Americas, a subsidiary of the German parent company. According to a Fed letter, written in June 2013, accessed by the Journal, the unit was not assessing the value of collateral correctly while reporting the value of high-risk loans.

"Most concerning is the fact that although the root causes of these errors were not eliminated, prior supervisory issues were considered remediated and closed by senior management," the December 2013 letter stated.

The revelations regarding the firm's "shoddy" financial reporting come just a few days after a Senate sub-committee investigation found that more than a dozen hedge funds, with assistance from Deutsche Bank and Barclays (NYSE:BCS), had used dubious financial products, known as "basket options," to claim billions of dollars in unjustified tax savings and circumvent rules meant to limit risky bets.