"The involvement of the United Kingdom’s Financial Services Authority... appears to have hampered the U.S. government’s investigations and influenced DOJ’s decision not to prosecute HSBC."
The Congressional investigation said that "the involvement of the United Kingdom’s Financial Services Authority in the U.S. government’s investigations and enforcement actions relating to HSBC, a British-domiciled institution, appears to have hampered the U.S. government’s investigations and influenced DOJ’s decision not to prosecute HSBC".
Additionally, the report found that George Osborne "intervened in the HSBC matter" by sending a letter to Federal Reserve Chairman Ben Bernanke "to express the UK’s concerns regarding U.S. enforcement actions against British banks".
According to the report, the FSA emphasized that HSBC was "the second most systemically important bank in the world" and that prosecution could result in a "global financial disaster".
In an email at the time, a US Treasury member said: "While the FSA folks did not argue specifically against a prosecution, it was clear they were very concerned about the reverberations such an action could have within the financial system, and they asked for urgent high level discussions with DOJ on the matter."
HSBC instead paid a $1.92bn fine in 2012 and did not face criminal charges.