The move followed a motion by Senator SABO MOHAMMED from Jigawa South, who alleged that the concession process was not transparent.
Senator MOHAMMED alleged that due process was not followed and that such a move would ridicule the anti-corruption fight by the government.
In his contribution; Senator DINO MELAYE of the APC from Kogi West, said Nigeria was about to witness another round of fraudulent sales of national assets to government cronies.
In passing the resolution, the Senate mandated an ad hoc committee to determine how and why such a deal was sealed and the criteria used to select the beneficiaries of the concession exercise, which were named as AGIP/ENI and OANDO.
The Senate noted that its major concern is the lack of clarity on whether the deal on concession agreement of the Port Harcourt Refinery or an agreement to build a new refinery.
It called for a halt of all processes tied to the transaction until the outcome of the investigation by its committee.
