EFCC Abdulrasheed Bawa appeared before Justice Sedoton Ogunsanya of the Ikeja High Court in Lagos on Sept 21.
Bawa is testifying as a key prosecution witness in an alleged N1.4 billion oil subsidy fraud case.
Nadabo Energy and its chairman Abubakar Peters, presenting fake documents, allegedly collected the amount from the federal government as oil subsidy.
They are also accused of inflating the quantity of petrol purportedly supplied to the Federal Government to 14,000 metric tonnes.
Bawa investigated the case when he was an operative of the EFCC.
The oil subsidy scam probe has been on since 2015, and many companies and individuals are facing similar prosecution.