An official says the Nigerian government owes its state-run oil firm more than $8.1 billion in gasoline subsidy payments.
The Nigerian National Petroleum Corporation official, who insisted on anonymity because of the sensitivity of the matter, said Tuesday that the debt is straining its ability to import gasoline.
Despite producing about 2.4 million barrels of crude oil a day, Nigeria imports most of its gasoline because its refineries are unable to meet the nation's demand.
The official said the debt has added to the corporation's financial burden after private companies stopped importing earlier this year.
He said the corporation, which used to account for 60 percent of Nigeria's imports, now accounts for all of them.
Nigeria's finance ministry could not immediately be reached for comment Tuesday.