Nigeria has filed charges against former US Vice-President Dick Cheney over a scandal involving a former subsidiary of Halliburton energy firm.
The case, brought by the country's anti-corruption agency, centres on engineering firm KBR, which admitted bribing officials.
Mr Cheney's lawyer has called the allegations "entirely baseless".
Mr Cheney was Halliburton's chief executive before becoming vice-president to George W Bush in 2001.
The Economic and Financial Crimes Commission (EFCC) said it had filed 16 charges against Mr Cheney, Halliburton Chief Executive David Lesar, and two other executives.
It also filed charges against Halliburton as a company and four associated businesses.
KBR last year pleaded guilty to paying $180m (£115m) in bribes to Nigerian officials prior to 2007, when it was a subsidiary of Halliburton. The firm agreed to pay $579m (£372m) in fines related to the case in the US.
But Nigeria, along with France and Switzerland, has conducted its own investigations into the case.
Mr Cheney's lawyer, Terence O'Donnell, said US investigators had "found no suggestion of any impropriety by Dick Cheney in his role of CEO of Halliburton".
"Any suggestion of misconduct on his part, made now, years later, is entirely baseless," Mr O'Donnell said.
The bribes concerned the construction of a liquefied natural gas (LNG) plant in southern Nigeria.
KBR and Halliburton have now split, and Halliburton says it is not connected with the case against KBR.
Halliburton denies involvement in the allegations.
It has complained that a raid on its office last month by EFCC officials was "an affront against justice".
Nigeria is a member of the oil cartel Opec and is one of the world's biggest oil exporters.