The fake press release, dated June 15, claimed Barrick had sold its Zambian copper mine to Metalinvest Capital Corporation and Zambia’s National Pension Scheme Authority (NAPSA) for $895 million in cash.

“We don’t know who’s behind this and we have alerted the relevant securities regulators and law enforcement authorities,” a Barrick spokeswoman told Reuters in a statement.

NAPSA – a government-owned pension fund – issued a statement saying it had not entered into any such transaction nor been involved in any such discussions.

“We would like to urge members of the public to ignore the said press release and treat it with the contempt it deserves,” the acting director general wrote, adding that the pension fund would seek to ensure the perpetrators were prosecuted.

Metalinvest has no knowledge of the deal and is launching its own investigation, founder and director Mohamed Matongo said in an email to Reuters.

“It has come as a great surprise to me that my company name is being mentioned in a transaction that we have no knowledge about,” he said.

Barrick was last year seeking buyers for its Lumwana copper mine, but in February Chief Executive Mark Bristow told Reuters he would not necessarily sell it, and might instead look for a partner in Zambia or a deal with a copper processor.