Nigeria’s anti-corruption agency has filed new charges in the case against the oil giants Royal Dutch Shell and ENI.
The corruption allegations relate to the $1.3bn (£1bn) purchase of a Nigerian oil block in 2011.
These are the latest charges in a complex investigation spanning several countries. Nigeria’s Economic and Financial Crimes Commision (EFCC) has accused the companies of a conspiracy to commit a felony and official corruption.
Royal Dutch Shell declined to comment.
The Italian firm ENI said in a statement that it had not been informed of the latest charges but reaffirmed the “correctness of its conduct” when purchasing the oil block - considered one of Nigeria’s best energy prospects.
The main accusation is that the two companies knew when they paid money to the Nigerian government that the cash would then be funnelled to individuals essentially as bribes.
Both firms have previously denied the accusations, stating they simply made the payment to the government and were unaware of any other arrangements.
Recently, the Nigerian government seized the block - ordering a halt to operations pending the outcome of the corruption cases.
Both Royal Dutch Shell and ENI are appealing against the decision.