OSP’s Evidence Helped Secure Asante Berko’s US Bribery Conviction

The Office of the Special Prosecutor (OSP) has disclosed that it provided investigative and evidentiary support to the United States Federal Bureau of Investigation (FBI), contributing to the conviction of former Tema Oil Refinery (TOR) Managing Director, Asante Kwaku Berko, in a US bribery case.

The OSP said its assistance was provided through Ghana’s mutual legal assistance framework and was acknowledged by the United States Department of Justice (DoJ) as having made a significant contribution to the prosecution.

In a public notice issued on Monday, August 10, 2026, the OSP said the DoJ had acknowledged its role as providing “significant assistance to this prosecution.”

A federal jury in Brooklyn, New York, convicted Berko on August 6, 2026, for conspiring to pay and paying more than US$1 million in bribes to several Ghanaian officials between 2014 and 2015.

The bribery scheme was linked to the development and financing of a power plant in Ghana under an agreement between the Government of Ghana and Turkish energy company Aksa Enerji Uretim A.S., a client of US-based investment bank Goldman Sachs.

According to the OSP, its collaboration with the FBI largely took place behind the scenes, with Ghanaian authorities providing investigative information and evidence to support the US prosecution.

The OSP said the case demonstrates the importance of international cooperation in investigating and prosecuting cross-border corruption.

It added that the outcome highlights the value of mutual legal assistance mechanisms, which enable law enforcement agencies across jurisdictions to share information and evidence in corruption-related investigations.

Berko, who holds both Ghanaian and US citizenship, faces a maximum prison sentence of 30 years following his conviction.

He is scheduled to appear before the US court on November 10, 2026, for sentencing.