Lekoil said it received a letter from the minister of petroleum saying Metallon's stake build - which began in March 2020 and resulted in the Zimbabwe-focused gold miner holding 15.1% of Lekoil - must be compliant with ministerial guidelines.

"In the event that Metallon's acquisition... has not complied with Nigerian legislation and in the absence of any suitable remedial action, sanctions could be imposed directly on the company by the Ministry of Petroleum Resources," Lekoil said in a statement.

(Reporting by Helen Reid; Editing by Jan Harvey)