The banks ended up closing or restricting the accounts and cooperated with the subcommittee, offering comments on individual transactions.

Image The Libyan leader Col. Muammar el-Qaddafi, left, and President Omar Bongo of Gabon in 2007. Credit... Eric Feferberg/Agence France-Presse — Getty Images

In all cases, the Senate report says, the banks ignored controls intended to prevent money laundering and related screens on PEP, meaning politically exposed persons  high-risk clients from corrupt countries.

The report recommends strengthening regulations against money laundering at banks and revoking exemptions for lawyers and other third parties from restrictions on money laundering in the USA Patriot Act. It recommends that Congress pass laws requiring people who form corporations to disclose the true owners.

The report, brimming with bank statements and internal e-mail messages, contains four case studies.

“Together, these four case histories demonstrate the need for the United States to strengthen its PEP controls to prevent corrupt foreign officials, their relatives and close associates from using U.S. professionals and financial institutions to conceal, protect and utilize their ill-gotten gains,” it says.

The report details how Teodoro Nguema Obiang, the son of Teodoro Obiang Nguema Mbasogo, the president of Equatorial Guinea, used lawyers, bankers, real estate agents and escrow agents, all Americans, from 2004 through 2008 to move more than $110 million into the United States, including $100 million through Wachovia and Citibank.