US regulators fined Deutsche Bank $55 million Tuesday for misstating important financial data on loss risks during the financial crisis in 2008.

The Securities and Exchange Commission said the German bank understated its potential losses on a leveraged portfolio of derivatives that came under a credit protection program.

As markets deteriorated during the year, the SEC said, the bank changed the way it reported the loss risks on the portfolio and eventually stopped adjusting the risk levels altogether.

That left the reports understating potential losses "estimated to be in the billions of dollars," the SEC said.

"At the height of the financial crisis, Deutsche Bank's financial statements did not reflect the significant risk in these large, complex illiquid positions," said Andrew Ceresney, director of the SEC’s Division of Enforcement.

"Deutsche Bank failed to make reasonable judgments when valuing its positions and lacked robust internal controls over financial reporting."

Deutsche Bank said it had stopped estimating the potential losses because it did not believe there was a reliable method to make the calculation in light of deteriorating market conditions in late 2008 and early 2009.

The bank added that "has enhanced policies, procedures and internal controls regarding the valuation of illiquid assets."

It did not admit or deny the charges outlined by the SEC.