The managing director of Capital Oil and Gas Limited, Ifeanyi Ubah has been released by the Department of State Services.
Ikechukwu Onyia, an aide of the businessman, says Ubah was released Monday night after spending more than five weeks in detention.
The DSS had arrested Ubah over alleged diversion of petroleum products worth eleven billion naira.
While in detention, the agency said Ubah undermined national security and public order through his conduct.
However, the businessman filed a lawsuit against the security agency for detaining him unlawfully.