Top diamond magnates in West Africa have entered Sierra Leone with the aim of getting the alleged diamond out

Government official

"The Ministry of Mineral Resources has put all security measures in place to trace the whereabouts of an alleged 1,000 carat diamond said to have been found on April 22," a senior official at the ministry told Reuters news agency.

If true, the gem would be the second largest ever found.

The biggest would remain the 3,107 carat "Cullinan" diamond found in South Africa in 1905, followed at the moment by the 995 carat "Excelsior" gem and the 969 carat "Star of Sierra Leone".

110-carat diamond

The BBC's Lansana Fofana in Freetown says the diamond is said to have been found in the eastern district of Kono.

He says that the police have now been joined by a government team of mines monitors in the search for the diamond across the country.

A new system for regulating diamond exports was introduced in 2000

On Friday morning, police and senior officers were locked in a meeting in Freetown as the search intensified, he said.

On Monday , the government said it had officially exported a single 110-carat diamond worth several million dollars, for the first time in over a decade of war.

It was found in the same district as the latest diamond and was exported to Europe through official channels.

Monday's sale had raised hopes that post-war measures aimed at regulating the diamond trade were beginning to work.

Massive search

"The ministry has been informed some top diamond magnates in West Africa have entered Sierra Leone with the aim of getting the alleged diamond out.

"Border security forces together with the immigration authorities have also been put on alert," a government official said.

Deputy Minister of Mineral Resources, Foday Yukella, said he had heard that the diamond allegedly discovered this week was only 102 rather than 1,000 carats.

"But as a government we are undertaking a massive search for the whereabouts of such a diamond," he said.

'Blood diamonds'

Sierra Leone has been a rich source of diamonds for decades and rebels in the former British colony sold gems - so-called "blood diamonds" - to fund a brutal 10-year civil war which officially ended in January this year.

Miners hope a diamond will change their lives

Most of Sierra Leone's diamonds are shipped to the Belgian port of Antwerp, the world's biggest market for uncut diamonds.

A certification system was set up in 2000 with United Nations help to stem the flow of "blood diamonds" and the government is keen to ensure gems are exported officially.

According to figures released this week legal exports in 2001 were worth $26 million, more than twice the $10.1 million in 2000 and a twenty-fold increase on the $1.2 million in 1999.

The diamond exported from Sierra Leone on Monday was described by Mines Minister Mohammed Deen as being the size of a substantial pebble.

But the real importance of the exported diamond may be symbolic.

The war in Sierra Leone was driven by the search for illegally-mined diamonds, and during the conflict almost all of the country's gems were smuggled out through neighbouring states.