The EFCC and the Nigeria Extractive Industries Transparent Initiative (NEITI) have are battling to locate $12.9 billion dollars payment to NNPC.
Both EFCC and NEITI have raised a 12-man panel to trace the cash.
The said money was paid by the Nigerian Liquefied Natural Gas (NLNG).
Some former ministers and past top officials of NNPC may be invited by the EFCC to shed light on the matter.
The $12.9b was remitted to NNPC between 2005 and 2013.
The Federal Government have said the money was not paid to her nor put into the Federation Account.
A source privy to the investigation said, “Preliminary investigation showed that NNPC officially confirmed the receipt of the $12.9billion.
“The oil corporation also admitted that it did not remit the funds.”
“NEITI will provide records at its disposal.
“We have a lot of issues to look into but the $12.9billion is certainly a priority.
“As at 2012, the NLNG cash paid to NNPC was $11.63billion but further investigation confirmed that it hit $12.9billion by 2013.
Some of the issues were contained in the NEITI 2015 Annual Activity Report, which was obtained last night.
The report reads in part: “NEITI audit reports confirmed that the sum of $11.63billion has been received by NNPC.
“The said amount has not been remitted to the Federation Account as required by law.
“These findings have been communicated to the Federal Government.
“NNPC assigned its 55% equity in OMLS 4, 26, 30, 34, 38, 40,41, 42 between 2010 and 2012 under the SPDC /JV Agreement.
“The value of divestment was assessed by DPR as $1,847,785,233.97 but only the sum of $100million was paid in 2014.
“Another $100million was not paid into the Federation Account but to NNPC/NPDC Special Account.
The source added that there is a strong suspicion that the cash might have been used for miscellaneous expenses, including election financing.