Nigeria's oil and gas industry is under scrutiny by lawmakers, following reports of discrepancies in the accounts of the state-owned Nigerian National Petroleum Corporation. The public hearings, which started last week, have opened a window into the extent of fraud and corruption in the industry.
A special parliament committee is investigating alleged misappropriation of billions of dollars in state revenue from the oil and gas sector since 1999, when Nigeria returned to civilian rule after decades of military dictatorship.
The committee is also focusing on alleged widespread irregularities in the production, import, export and distribution of Nigeria's oil and gas.
The anti-corruption unit, the Economic and Financial Crimes, says an estimated $500 billion was stolen between 1960 and 2007 in Nigeria, the world's eighth largest oil exporter.
The chairman of the House of Representatives ad-hoc committee on NNPC, Ugo Aguma, could not hide his frustration at one of the public hearings in Abuja.
"It amounts to executive recklessness on the side of the NNPC to go contrary to the constitution of the Federal Republic of Nigeria by appropriating by itself over $4 billion of dividends accruable to the Federal Republic of Nigeria from the NLNG [Nigerian Liquefied Natural Gas]," said Aguma.
NNPC, a multibillion-dollar organization with 11,000 employees, has long been Nigeria's economic lifeblood. It controls virtually all aspects of the oil and gas industry in Nigeria but remains opaque to most Nigerians.
Anti-corruption campaigners say Nigerian rulers have established a lock on the country's oil riches and amassed a fortune at the expense of the impoverished citizenry.
Nine out of 10 Nigerians live on less than $2.00 a day, their lives blighted by poor infrastructure and a lack of public services resulting from decades of corruption.
President Umaru Yar'Adua, who promised to tackle graft when elected in 2007, has been criticized for making slow progress on the issue.