A Nigerian court has ordered the temporary forfeiture of assets and the transfer of operations of a long-disputed oilfield owned by Shell and Eni, among others, to the federal government, court papers released on Thursday showed.

The court orders will last until Nigeria’s anti-corruption agency concludes an investigation into how the current owners acquired oil prospecting licence (OPL) 245, the papers said.

This is the latest of many inquiries, including by Dutch and Italian authorities, into the 2011 purchase of the OPL 245 block which could hold up to 9.23 billion barrels of oil, according to industry figures.

The Shell Petroleum Development Company of Nigeria declined to comment. Eni did not immediately respond to a request for comment.