Information has it that Nigeria is owed a total of $12.7 billion by more than a dozen companies for allegedly not declaring exports of crude oil to the United States between 2011 and 2014.
According to court documents seen by Reuters on Wednesday, which are part of a lawsuit the Nigerian government filed on June 7 against one of the companies - Nigerian AGIP Oil Company, a subsidiary of Italy's ENI and it was not immediately clear from the documents exactly how many of the companies Nigeria is suing.
The suit alleges that companies exported a total of 57 million barrels oil crude oil to the United States over the period and did not declare all of this to Nigerian government as required by law, according to the documents.
ENI had said on Tuesday the claim against it amounted to $160 million, that there were "no grounds" to the claim and that it would contest it in court. ENI was not immediately available for comment on Wednesday.
U.S. oil company Chevron and France's Total have both previously been named as defendants but were not immediately available for comment on Wednesday.