The PricewaterhouseCoopers Investigative Forensic Audit into Allegations of Unremitted Funds by NNPC into the Federation Account was commissioned by the Auditor-General for the Federation in 2014, in direct response to the explosive allegation made by then-CBN Governor Sanusi Lamido Sanusi to the Senate on 19 November 2013 that approximately $49.8 billion (later revised by Sanusi to $20 billion) had been withheld from the federation account by NNPC between January 2012 and July 2013. Sanusi's suspension by President Jonathan in February 2014 turned the affair into a constitutional crisis. The audit was conducted by PricewaterhouseCoopers Nigeria, operating from its Lagos office.
The PwC final report was dated February 2015 and delivered to the Auditor-General. It was released publicly in April 2015—weeks before the general election that brought Buhari to power—when Premium Times, Sahara Reporters, and Vanguard published the full text after it was transmitted to the Senate. The report's headline finding was that NNPC had not remitted $18.53 billion to the federation account over the audit period. However, PwC identified legitimate deductions—including pipeline repair costs, NPDC operating expenses, and crude oil swap settlement shortfalls—that partially explained the discrepancy. The net unresolved gap attributable to unexplained non-remittances was assessed at approximately $10.8 billion, still an enormous sum. PwC found that NNPC operated approximately 30 accounts not disclosed to the federation account, and that the domestic crude oil allocation sold under OPA arrangements generated revenues that were not transparently recorded or remitted.
The report confirmed Sanusi's core allegation while significantly reducing the headline figure and providing methodological context that NNPC cited in its defense. The audit did not constitute a criminal investigation and made no findings of individual criminal liability, though it identified multiple instances warranting further forensic investigation. The PwC report was tabled before the Senate and published. Sanusi called for full implementation of its investigative leads in May 2015. The report contributed to ongoing EFCC investigations into the petroleum sector and the eventual trial of Diezani Alison-Madueke in the United Kingdom, though Nigeria's domestic prosecutorial follow-through remained limited.