A claim that the world's largest diamond has been found in South Africa has yet to be followed by any evidence, but has produced plenty of speculation, accusations of fraud and even a a blindfolded journey reminiscent of a bad spy novel.

Nearly six weeks after the announcement of the discovery of an 8,000-carat diamond — more than twice the size of the world's largest — the South African diamond expert called in to verify the claim declared he would have nothing more to do with the affair. He says he never glimpsed the stone and one photo he did see looked like a lump of resin.

The British businessman who made the initial announcement says he has laid fraud and theft charges against his former associates.

"I wish I knew what was going on," Ernie Blom, chairman of the South African Diamond Council and president of the World Federation of Diamond Bourses, said Monday. "They created enormous excitement and expectation in the world and the whole thing has fizzled out. I am not sure what the truth is."

It's not impossible that a big rock has been found in South Africa. The world's largest diamond, the 3,000-carat centerpiece of the British crown jewels, was discovered near Pretoria in 1905. South Africa is the world's third largest diamond producer after Botswana and Russia.

Blom, who had negotiated a deal to verify and market the stone, said he persistently asked those involved for various documents relating to the ownership of the diamond and the mine.

"I didn't receive anything. Any legitimate operation would have immediately been able to produce the documents," he said.

The last straw for Blom came when British businessmen Brett Jolly, who had made the initial announcement, took a Johannesburg reporter on what was to have been a trip to see the diamond — something he had asked other media organizations to pay to do.

The resulting story in the national newspaper The Times related the reporter being blindfolded for part of the journey and caught in a screaming match between Jolly and one of his associates, Andre Harding.

Harding, who is said to have decades of mining experience, told the reporter that he was being followed by "government agents" and had the diamond in a safe welded to his car.

He made a hurried stop at the side of a road to show the stone to the reporter and tried to prove that it was a diamond using a simple testing device. According to the newspaper, Harding didn't taken the cap off of the tester and had preset it to flash "diamond."

When Blom was shown a picture taken by the reporter of the alleged stone, he described it as a "disgusting lump of resin."

"That's when I decided to withdraw," Blom told The Associated Press Monday.

Whatever the reporter was shown "was fake," Blom said, though he has said he still believes a large diamond exists.

Harding would not comment Monday, noting the case could go to court.

Jolly has so far produced only a low-resolution photograph of a multifaceted, green glassy crystal. He has refused to say exactly where it was found or name the mine and its owners. Now, he says he has laid charges of theft and fraud against Harding and another associate.

"I am very confused. I don't know what to think. But I still believe there is a stone out there," Jolly told the AP Monday.

Jolly said he has the option to purchase the land on which the alleged diamond was found and is concerned a scam to push up property prices is afoot. He also suggests that perhaps the diamond has been smuggled out the country to avoid various taxes and other costs.

Jolly won't say at which police station he laid the charges and by early Monday evening police could not confirm that a case had been opened.