A Christian pastor has found one of the largest diamonds discovered in the world so far.

Pastor Emmanuel A Momoh is one of thousands of people who hunt for diamonds in Sierra Leone.

He found the 706-carat diamond, one of the 20 largest ever, in the alluvial mines in the Kono district.

The diamond was locked up in Sierra Leone's central bank in Freetown after it was presented to President Dr Ernest Bai Koroma last night by Paramount Chief Paul Saquee.

According to mines minister Alhaji Minkailu Mansaray, the diamond was discovered by Pastor Emmanuel A Momoh while he was taking part in alluvial mining at Koyadu village in Tankoro Chiefdom.

Receiving the diamond, President Koroma thanked the chief and his people for not smuggling the diamond out of the country. In a statement, the president underscored the importance of selling such a diamond in Sierra Leone itself, 'as it will clearly give the owners what is due them and benefit the country as a whole'.

The diamond has not yet been valued or named. The president said the selling process would be transparent and to the highest bidder. 

Freelance, or artisanal, miners are common in Sierra Leone's diamond-rich areas, reports the BBC. Momoh's find is the biggest in Sierra Leone since 1972, when the 969-carat Star of Sierra Leone unearthed.

The largest diamond ever, 'Sergio', a black diamond weighing 3167 carats, was found in Brazil in 1893.

The famous Cullinan diamond found in South Africa in 1905, at 3,106 carats, was cut into separate stones with two now in the sceptre and crown of the British Crown Jewels. 

An 813-carat diamond sold for £51 million at auction in London last summer.

Sierra Leone was traumatised for years by a civil war financed by the sale of 'blood diamonds'. More than 120,000 people are believed to have lost their lives. 

The present government is taking a firm line against illicit diamond trading.