BEIJING - The Chinese are said to have discovered gunpowder, paper and the compass, but it may be too early to claim they discovered America.
A map purported to date from 1418 suggesting a Chinese fleet sailed to America decades before Christopher Columbus is being displayed in Beijing, but the piece of yellowing paper is the centre of a storm of criticism over its authenticity.
The map, which is said to be an 18th-century copy of the 1418 original, shows both North and South America in unusual detail.
It was bought in 2001 by Chinese lawyer and art collector Liu Gang, who says he did not realise its significance until reading a book by a British writer who claimed a Chinese admiral beat Columbus to the punch.
Gavin Menzies, author of the bestseller "1421: the Year China Discovered America," says Admiral Zheng He led a fleet of 30,000 men aboard 300 ships to the American continent in the 15th century to expand Ming China's influence.
"This map embodies information I believe will help us understand Zheng He's seventh voyage," Liu, who bought the map for $500 ($723), told a news conference.
"The map shows us the Chinese explorer has been to America years before Columbus. The map also shows us the Chinese understanding of the entire world." Yet whether Zheng, a Muslim eunuch known to have sailed as far as southern Africa, beat Columbus to America by more than 70 years is bitterly debated.
Some academics point to a score of inconsistencies in both the book and the map, saying, for example, the map uses language that does not fit the style of Ming China.
"I'm inclined to think that it's a fake," said Geoff Wade, a visiting senior research fellow at the National University of Singapore. "There's absolutely no evidence that the Zheng He voyages went anywhere past the east coast of Africa." Historical records show that from 1405 to 1433, Zheng, under the orders of Emperor Zhu Di, led China's imperial Star Fleet on seven epic voyages.
Now, Zheng's voyage is being used by the Chinese government for political purposes, as a way of showing the country's rising power will not threaten its neighbours, Wade said.
"Zheng He is being pushed all over Asia as part of the Chinese foreign ministry's foreign policy, with the statement that Zheng He's voyages to Asia and beyond were peaceful," he told Reuters by telephone.
Liu, who showed only a copy of the map, saying the insurance company would not let him take the real thing out of its bank vault, is convinced of its authenticity and says even Jesuit missionary Matteo Ricci based his maps on Zheng He's.
Ricci is thought to be the first person to draw a map of the world for the Chinese in the 1500s.
Liu says he believes his map could lead to more evidence supporting the claim the Chinese discovered America.
"I strongly believe that other maps exist, that other books exist but people may not see their importance," he said. "I published this map to wake up those men."