Researchers at Waikato University are conducting tests on the paper and ink used for a Chinese map which indicates that a Chinese eunuch discovered America.
The copy of a map made in 1763, of a map dated 1418 - to be made public in Beijing today - may show that Admiral Zheng He discovered America more than 70 years before Christopher Columbus, the Economist reported.
If the tests and authentication by other experts showed the map - with a clear depiction of the Americas, New Zealand, Australia, Americas, Africa and Europe - to be genuine, it would overturn centuries of European teaching. Traditional histories record that Columbus found the New World in 1492, Dias discovered the Cape of Good Hope in 1488 and Magellan set off to circumnavigate the world in 1519.
Gunnar Thompson, a researcher of ancient maps and early explorers, said if the map was genuine it would revolutionise thinking about 15th-century world history.
Results of the mass spectrography analysis at Waikato University to date the materials on which the map was copied is due to be announced next month, but will only be direct evidence of the paper and inks used in the copy.
Five Chinese academic experts on ancient charts have noted that the 1418 map puts together information that was available piecemeal in China from earlier nautical maps, going back to the 13th century and Kublai Khan, who was himself an explorer, the Economist said.
The naval fleets of Zheng He roamed the oceans between 1405 and 1435, and his exploits - well documented in Chinese history - were recorded in a 1418 book called The Marvellous Visions of the Star Raft.
The copy of the map will be unveiled in Beijing today and at Britain's National Maritime Museum in Greenwich on Wednesday. Six Chinese characters in the upper right-hand corner of the map say this is a "general chart of the integrated world". In the lower left-hand corner is a note that says the chart was drawn by Mo Yi Tong, imitating a world chart made in 1418 which showed the barbarians paying tribute to the Ming emperor, Zhu Di.
The copyist differentiated between what he took from the original from what he added himself.
The copy of the map was bought from a small Shanghai dealer in 2001 by Liu Gang, an eminent Chinese lawyer who collects maps.