A court in Egypt has cancelled a goldmine concession held by a Canadian exploration company.
Centamin, which is listed in London and Toronto, said on Tuesday that the court did not have the jurisdiction to cancel it.
AAP reports Cairo's administrative court annulled the 30 year contract, which was signed under former President Hosni Mubarak.
Following the decision, Centamin's shares plunged by around 35% on the London Stock Exchange before trading was suspended.
However, Centamin said that a final decision on the Sukkari contract had not yet been made.
"No details of a final decision (regarding the contract) are available," it said in a statement to the London stock exchange.
Centamin said mining operations would continue until further information was available.
Production at Sukkari, the largest goldmine in Egypt, began in 2009.