The bank on Wednesday struck a combined $612 million settlement with U.S. and British authorities in the latest case to emerge from a broad international investigation.

In an embarrassing blow, its Japanese subsidiary also pleaded guilty to criminal wrongdoing in its settlement with the Justice Department. The RBS subsidiary, a hub of rate-rigging activity, agreed to a single count of felony wire fraud to resolve the case.

The settlement reflects the Justice Department’s renewed vigor for punishing banks ensnared in the rate manipulation case. In December, a Japanese subsidiary of UBS pleaded guilty to felony wire fraud as part of a larger settlement.

As authorities built the RBS case, they seized on a series of incriminating yet colorful emails that highlighted an effort to influence the rate-setting process, a plot that spanned multiple currencies and countries from 2006 to 2010. One senior trader expressed disbelief at reaping lucrative profits from the scheme, saying “it’s just amazing” how rate “fixing can make you that much money,” according to the government’s complaint. Another trader, after pressuring a colleague to submit a certain rate, offered a reward of sorts: “I would come over there and make love to you.”

In a statement on Wednesday, the U.S. regulator leading the case slammed the bank for manipulating benchmarks such as the London Interbank Offered Rate.

“The public is deprived of an honest benchmark interest rate when a group of traders sits around a desk for years falsely spinning their bank’s Libor submissions, trying to manufacture winning trades. That’s what happened at RBS,” David Meister, the enforcement director of the Commodity Futures Trading Commission, said in the statement.