The Justice Department said Thursday it won't prosecute Wall Street firm Goldman Sachs or its employees in a financial fraud probe.

In a written statement, the department said it conducted an exhaustive investigation of allegations brought to light by a Senate panel investigating the 2008-2009 financial crisis.

"The department and investigative agencies ultimately concluded that the burden of proof to bring a criminal case could not be met based on the law and facts as they exist at this time," the department said.

But the department added that if additional or new evidence were to emerge, it could reach a different conclusion about prosecuting Goldman if warranted.

A Senate subcommittee chaired by Sen. Carl Levin, D-Mich., in April 2011 found that Goldman marketed four sets of complex mortgage securities to banks and other investors but that the firm failed to tell clients that the securities were very risky.