Nigeria's President Goodluck Jonathan has ordered a forensic audit of the national oil company following allegations by Central Bank Governor Lamido Sanusi that $20 billion had gone missing.

Last month, Sanusi presented evidence to the parliament, accusing the Nigerian National Petroleum Corporation’s (NNPC) of failing to account for $20 billion of the $67 billion of oil sold between January 2012 and July 2013.

The oil company has repeatedly denied the allegations, saying they showed “little understanding of the technicalities of the oil industry.”

Jonathan has given authorization for “reputable international firms” to carry out the audit on Wednesday, without naming the companies.

Sanusi was suspended last month after he told the senate committee about the alleged NNPC’s failure to remit the $20 billion into government treasury.

The presidency, however, said in the statement that Sanusi's suspension had “absolutely nothing” to do with his “patently untrue” allegations, and that he was suspended for unrelated “financial recklessness” and “gross misconduct” at the Central Bank.

The International Energy Agency announced in July last year that stealing oil from Nigeria’s pipelines has inflicted a dramatic plunge in the output made by the Organization of the Petroleum Exporting Countries (OPEC), of which Nigeria is a member.

The Africa’s largest oil producer, which generates around 2 million barrels of oil, loses about USD 6 billion of its revenue each year, because of oil theft.