But critics say document that indicates China discovered the Americas is a fake
Liu Gang, the owner of an ancient map he believes is a copy of an integrated world map by Ming dynasty explorer Zheng He (1371-1435), hit out yesterday at critics questioning the document's authenticity.
Mr Liu said the map had been subject to accelerator mass spectrometry dating in tests in Singapore and the results showed it was probably drawn between 1730 and 1800. He said his map was drawn by Mo Yitong in 1763 and was a copy of Zheng's 1418 map.
Also defending the map in Beijing yesterday were Gavin Menzies, author of 1421 - The Year China Discovered the World, and Gunnar Thompson, director of the New World Discovery Institute in Washington.
Mr Liu contacted Mr Menzies and Dr Thompson via e-mail to take part in his research into the map after he was snubbed by historians on the mainland.
Mr Menzies admitted he had some initial reservations about the map because of the controversy. 'I looked through all those things that've been mentioned as possible concerns and I found there is no reason to believe they aren't all authentic to the original,' he said.