Orji Uzor Kalu, former governor of Abia state, is still in Kuje Prison in the federal capital territory (FCT).
A source confirmed this to TheCable on Monday, saying the supreme court has not sent the warrant of release to the prison authorities.
A federal high court in Abuja had sentenced Kalu, chief whip of the senate, to 12 years in prison after convicting him of money laundering and abuse of office.
However, his legal team had challenged the conviction, arguing that Mohammed Idris, the judge who handed down the ruling, lacked the jurisdiction to hear the case because he had been elevated to the appeal court at the time he sentenced Kalu to prison.
Last week, the supreme court held that held that the Fiat that was issued to Idris by Zainab Bulkachuwa, former president of the court of appeal pursuant to section 396(7) of the Administration of Criminal Justice Act was unconstitutional.