It's been reported that Libyan leader Muammar Qaddafi has billions of dollars hidden hidden in Tripoli--money that's helped him prolong his fight against the rebels. But today we're learning that Qaddafi has also stowed billions of dollars in Libyan oil revenues away in Western institutions, according to a 2010 summary of the state's $53 billion in global investments published by the advocacy group Global Witness and verified by The New York Times. The document reveals that Libya's sovereign wealth fund invested $1 billion in Société Générale, $292.69 million in HSBC, $171 million in JPMorgan Chase, and $43 million in Goldman Sachs. The state was also a key shareholders in companies such as General Electric, Halliburton, BP, and Nokia, and a holder of U.S. government bonds. The fund invested another $19 billion in Libyan and Middle Eastern banks.

The Western banks, not surprisingly, are not commenting on the report, citing customer confidentiality, though a Société Générale spokeswoman did say the French bank "deals with many sovereign funds and complies with all applicable rules and regulations," according to the Times. The paper adds that Libya's investments appear to have been legal at the time. Now, the BBC adds, the European Union, the U.N., and the U.S. have frozen those assets because officials believe Qaddafi and his family exercise substantial personal control over Libya's state-owned enterprises, including its sovereign wealth fund. One banker tells the BBC that Libya' assets are "locked down" pending word from the U.S. government.

Global Witness, for its part, says banks should be required to disclose the state funds that they manage to ensure that state revenue isn't "being stolen by corrupt leaders," and regulators should investigate whether the banks holding Libya's assets have done enough to prevent "transfers from state funds to accounts personally controlled by Qaddafi and his cronies." For more detail on the report, here's a BBC audio interview with a Global Witness representative: