Freetown: A Christian pastor has found one of the world's largest uncut diamonds – weighing 706 carats – in Sierra Leone's eastern Kono region.

The stone, a photograph of which was posted on the president's official website, is being stored in the country's central bank, government sources said.

A local chief from Kono handed the stone to President Ernest Bai Koroma on behalf of Emmanuel Momoh who made the discovery. The government plans to auction it.

The presidency said in a statement on Thursday that Koroma thanked the chief who acted as an intermediary for not smuggling it out of the country.