Courthouse News reported two pensions filed suit against Cobalt Energy and its PEU sponsors:
On the morning of August 5, 2014, Bloomberg reported that an anti-corruption organization had determined that Cobalt had made an apparent bribe to the Angolan government, because Cobalt had paid the Angolan government millions of dollars to support an Angolan research center that Cobalt could not confirm actually exists," the complaint states.
On Nov. 5, Cobalt disclosed that contrary to its previous claims that one of its Angolan wells was oil-rich, testing revealed the well contained neither oil nor gas.
PEU Report wrote about Cobalt numerous times with one post exploring possible bribes.
Update 3-29-15: A U.S. newspaper columnist reported "Tom Burgis of The Financial Times has a powerful new book, “The Looting Machine,” asserting that firms, including Goldman Sachs and Carlyle Group, backed an oil company called Cobalt in investing in oil operations in which Angolan officials secretly held stakes worth staggering sums." It's not an assertion.