Nigeria has secured a major victory in the long-running legal dispute over the $3,050-megawatt Mambilla Hydroelectric Power Project, with an International Chamber of Commerce (ICC) tribunal rejecting a $400 million claim by Sunrise Power and Transmission Company Limited and its principal, Mr Leno Adesanya.
The tribunal, in its final award delivered on September 17, 2026, held that a settlement agreement and its addendum relied upon by Sunrise were not binding on the Federal Government because the former ministers who signed the documents lacked the authority to commit Nigeria without presidential approval.
Airtel Tenancy
The tribunal also found that the settlement agreement was tainted by corruption and violated Nigerian public policy, making it unenforceable.
The dispute centred on the Mambilla project, one of Nigeria’s largest proposed infrastructure schemes, with an installed capacity of 3,050 megawatts.
Sunrise had demanded $400 million from Nigeria, comprising a $200 million settlement sum and another $200 million described as a “default sum”, in addition to interest at 10 per cent annually, compounded daily.
The claim was separate from another arbitration in which Sunrise is seeking more than $2.7 billion from Nigeria.
According to the Attorney-General of the Federation and Minister of Justice, Prince Lateef Fagbemi, SAN, the dispute had its origins in Sunrise’s claim to a Build-Operate-Transfer contract dating back to 2003.
The dispute subsequently generated court proceedings in 2007 and further arbitration proceedings, with the government maintaining that the prolonged legal battles had contributed to delays in securing financing and achieving financial close for the Mambilla project.
The Federal Government said financing from the China Export-Import Bank was conditioned on the resolution of the disputes surrounding the project.
Fagbemi said the prolonged delay had denied Nigeria the potential economic benefits of 3,050 megawatts of hydroelectric power, including increased electricity generation and industrial output.
In rejecting Sunrise’s latest claim, the ICC tribunal went beyond the question of contractual authority, making findings concerning alleged corruption surrounding the settlement.
According to the Attorney-General’s statement, the tribunal found that Adesanya had engaged in a prolonged pattern of bribery and corruption involving payments to senior Nigerian government officials connected with the Mambilla project.
It further found that a corrupt agreement was reached between Adesanya and former senior Nigerian officials involved in the settlement that formed the basis of the arbitration.
The tribunal also found that the alleged corrupt dealings extended to the origins of the Mambilla dispute, which it characterised as an established pattern of engaging influential government officials through financial incentives.
As a consequence of the findings, Sunrise and Adesanya were ordered to bear 75 per cent of Nigeria’s legal fees and expenses, together with interest at 10 per cent annually, compounded annually.
The tribunal also expressed the hope that the award would deter Adesanya and his companies from pursuing further proceedings against Nigeria that it considered frivolous.
Fagbemi described the ruling as a significant vindication of Nigeria’s position, saying the Federal Government would not accept contractual claims arising from agreements that were allegedly fraudulently procured or entered into without the required authority.
He credited President Bola Ahmed Tinubu with maintaining the position that Nigeria should not succumb to fraudulently contrived contractual agreements and claims arising from them.
The Attorney-General also said the President had ensured the provision of financial and logistical support for Nigeria’s defence of the arbitration.
Fagbemi said the Federal Ministry of Justice would continue to focus on protecting the country’s legal and public interests in major international disputes.
The latest award, however, does not resolve the separate arbitration in which Sunrise is seeking more than $2.7 billion in connection with the Mambilla project.
The outcome therefore represents a major ruling in one chapter of the protracted dispute, while the broader legal history surrounding the project remains unresolved.