A US expedition that claimed to have located the grave has abruptly cancelled its dig and withdrawn from Mongolia.
The whereabouts of the remains of the 13th-century warlord, who united the warring tribes of Mongolia before conquering territory from Russia to China, is one of archaeology’s greatest mysteries.
Legends that claim the tomb will never be found have been granted a new lease on life by the latest failure to find it.
The Genghis Khan Geo-historical Expedition obtained a permit from the Mongolian government to dig at Oglogchiin Kherem, 200 miles north of the Mongolian capital, Ulaan Baator.
But the mission, organised by Maury Kravitz, a former gold trader, and John Woods, a respected University of Chicago historian, suddenly ended at the start of this month after a string of calamities.
For a start, a two-mile-long wall infested with pit vipers protects the suspected site of the tomb. During the dig, expedition workers were bitten by the snakes. Cars rolled off hillsides for no apparent reason.
The final blow came after a former Mongolian prime minister, Dashiin Byambasuren, accused the team of desecrating a sacred site. "I regret that our ancestors’ golden tomb has been disturbed and the purity of our burial places tainted for a few dollars," he said. "This place should remain pure for the souls after death."
The only other attempt in modern times to find the tomb, an official Japanese mission in 1993, also failed after mysteriously calling off its search.
Mongol tradition dictates that Genghis Khan was buried with the spoils of his campaigns, ranging from jewelled Chinese weapons and gold coins from Samarkand to religious artefacts from Russian Orthodox churches.
"In each of the countries and cities and sovereign states he conquered, Genghis Khan brought back the wealth of that culture on two-wheeled wagons," Mr Kravitz told a Chicago magazine in June. "Not one thing has been found. Not a single bejewelled dagger. Not a single necklace. It all went into Mongolia and never exited."
Finding Genghis Khan has been an obsession for Mr Kravitz since 1954, when he was a US army private in Germany. He has built one of the world’s largest collections of Mongol books and artefacts. He has read and reread The Secret History of the Mongols, a 14th-century Chinese book, for clues on the grave’s location. Before his death in 1227, Genghis Khan gave elaborate orders to ensure his grave was never discovered.
Histories tell of 1,000 foot soldiers killed at the site of the tomb. When 800 more returned to Karakorum, then the Mongol capital, they too were slaughtered. Thousands of horses were raced over the grave to obliterate any trace, it is said.
Mongols fear the tomb’s finder would be cursed. "Some people would become very rich," said Baatariin Bayar, a Ulan Bator shopkeeper. "But I would be afraid to touch that soil, because bad things would follow me and my family."