World's Largest Uncut Diamond Denounced As Plastic Fake

After more than a month of speculation, the "world's largest diamond", said to be twice the size of the famous Cullinan, was yesterday denounced as a "piece of plastic" by the man at the center of the drama over its discovery.

Accusing former associates of a scam, a British property developer, Brett Jolly - who thought he was going to be fabulously rich as a result of the find - said he was going to lodge a complaint with the police. He claimed he was the victim of a fraud aimed at persuading him to buy the land in South Africa's North West province on which the so-called diamond was found.

The story began to unravel yesterday morning when a diamond expert hired to authenticate the gemstone announced he was withdrawing.

"I am of the opinion that the diamond could exist, but I suspect something is afoot," the president of the World Federation of Diamond Bourses, Ernest Blom, said in a statement. "It is with this in mind that I withdraw from the process completely and disassociate myself from any further press statements ... As a matter of course I will be taking legal advice on this matter."

After numerous telephone calls, the Guardian caught up with Mr Jolly on his mobile phone in the middle of a thunderstorm, on the road from Johannesburg to his home in Cape Town.

Offering a fuller account of the saga, he said that he had not actually seen the contentious stone until Thursday.

Frustrated by the failure of the two miners to show him or Mr Blom the stone, he had come to Johannesburg earlier this week to "sort the matter out". After something of a wild goose chase he had met the miners on a roadside, and they had presented him with what was claimed to be the 7,000-carat gem.

"They showed me a lump of plastic," Mr Jolly said. "It was clearly, clearly a lump of plastic. There was no way in the world it was a diamond."

He said the miners then produced a diamond tester. He said they had seemingly fixed it beforehand to give a positive reading, but forgot to take the cap off while they did the test, making a nonsense of the claim that the instrument showed it was a genuine diamond. "The cap was still on the bloody thing," Mr Jolly said.

The property developer explained that he had a marketing agreement with the two miners by which he had an option to buy the piece of land where the stone was said to have been found and was entitled to 10% of any gemstones found there.

"I think they were salting the mine, that's what I think," he said, referring to an old scam used to make an empty mine appear viable.

When it was pointed out that he was accusing them of a criminal offense, Mr Jolly said: "I'm going to the police on Monday morning." Asked why not before then, he said: "Because I'm very, very tired."