Johannesburg ? The party to raise money for Nelson Mandela’s children’s charity started with an odd guest list: Dining among the celebrities was Liberian warlord Charles Taylor, also known as the “Butcher of Monrovia.”

Before the night was over, supermodel Naomi Campbell says she had been given a pouch of “dirty-looking stones” by two men who knocked on her door as she slept.

Now South African authorities want to know why the man she passed them to aboard a luxury train kept the precious stones for 13 years — and whether they are “blood diamonds.”

Prosecutors hope details from that star-studded dinner at the presidential mansion on Sept. 26, 1997 — and what transpired later that night — will help prove Taylor traded in illegally mined diamonds to arm rebels in Sierra Leone.

The man who received the uncut stones, a well-respected South African businessman, Jeremy Ratcliffe, finally handed them over to authorities on Thursday after Campbell testified in Taylor’s war crimes trial under threat of contempt.

On Friday, tests determined with certainty that they are indeed diamonds.

“They were taken to the Diamond Board for authenticating and yes, they are diamonds and they are authentic,” Musa Zondi, a spokesman for the police special investigations unit, told The Associated Press.

But whether diamond experts will be able to trace their origins to the West African conflict zone remains far from clear.

In South Africa, the mere possession of a rough diamond is illegal because of possible links to conflict zones, money-laundering and other crimes — raising questions about whether Ratcliffe or even the 40-year-old Campbell could face legal proceedings.

“Obviously if a person is in possession of uncut diamonds in this country, that person has contravened the law. We will investigate the possible contravention,” Zondi said, adding that anyone found guilty could be fined up to $34,000 or jailed for up to 10 years.

The chances of pinning down the gems’ origin are remote, experts say.

There is no science yet for pinpointing the exact geographic origin of a diamond, according to Ricardo Baretzky of the South African firm Dialab, whose company has patented a method for taking a kind of “DNA” test of a diamond’s carbon print.