(CNN) -- The top Republican on the Senate committee that oversees the Justice Department issued a blistering criticism of Attorney General Eric Holder and his department for failing to pursue criminal charges against a giant global bank that admits violating federal laws by laundering money on behalf of Iran, Libya, Sudan and Myanmar.
Sen. Charles Grassley, R-Iowa, sent his stinging letter to Holder Thursday, calling it "inexcusable" for the department not to prosecute criminal behavior by the British banking giant HSBC. In a settlement reached Tuesday, HSBC agreed to pay the U.S. government $1.92 billion in a wide-ranging agreement. Any prosecution in the case was "deferred," meaning it is unlikely anyone from the bank will ever go to jail for wrongdoing.
"What I have seen from the department is an inexplicable unwillingness to prosecute and convict those responsible for aiding and abetting drug lords and terrorists," Grassley wrote.
"By allowing these individuals to walk away without any real punishment, the department is declaring that crime actually does pay," Grassley asserted.
The Justice Department had no immediate comment Thursday. Assistant Attorney General Lanny Breuer defended the settlement Tuesday in a New York news conference.
Breuer said, "HSBC is being held accountable for stunning failures of oversight."
HSBC Chief Executive Stuart Gulliver released a statement Tuesday, saying "we accept responsibility for our past mistakes."