Nigeria has charged two British nationals with fraud and money laundering over a failed gas project at the centre of a multi-billion-dollar arbitration award in London, the anti-graft agency said.
Suspect James Nolan appeared in court in Abuja on Monday while co-defendant Adam Quinn was charged in absentia.
The pair were arraigned over "their alleged complicity in the controversial $9.6bn arbitral award to Process and Industrial Development Limited by a United Kingdom commercial court", the Economic and Financial Crimes Commission (EFFC) said in a statement on Monday.
The agency said the accused - both directors of Goidel Resources Limited - had violated Nigeria's money laundering laws to help P&ID by failing to submit documents and disclose $125 000 in the firm's accounts to the authorities.
Both of them pleaded not guilty to the charges, the EFCC said. Quinn was represented by his lawyers.
Presiding judge Okon Abang remanded Nolan in custody until November 20 for further hearing.
The hearing was the latest stage in the long-running dispute between Nigeria and P&ID, widely reported to be registered in the British Virgin Islands, over a 2011 failed deal to build a gas plant in the oil and gas-rich west African nation.
In August, a British court gave the go-ahead for P&ID to seize $9.6bn in Nigerian government assets - a fifth of the country's foreign reserves --over the botched deal.
The agreement to build a processing plant to refine and supply Nigerian gas between the government and the company, set up in 2010 by two Irish partners, fell through in 2012.
An arbitration tribunal in England awarded the firm $6.6bn (5.9bn euros) in damages in January 2017 but P&ID said it has accrued interest, raising the overall figure to more than $9bn.
A London court in September granted a stay-of execution on the judgement pending an appeal by Nigeria.
Last month, a court in Abuja convicted two local representatives of P&ID over tax invasion and fraud and ordered that the company's assets be forfeited to the government.