He may have made the discovery seven decades before Columbus stumbled upon the New World.

    The map, which has gone on display in Beijing, is said to be a copy made in 1763 of a much older map dating back to 1418. It clearly depicts Africa, Europe and the Americas.

    If it's proven to be authentic, the map would provide strong evidence to suggest that the famous Ming Dynasty mariner, Zheng He, beat Christopher Columbus, who arrived in America in 1492, to the discovery of the New World. 

  Liu Gang, a Chinese lawyer and map collector, bought the map in an antique store in Shanghai in 2001 for about 500 US dollars.

    Liu Gang thinks the map supports the thesis of British author, Gavin Menzies, who in a 2003 book argued Zheng He was the first person to circumnavigate the globe and discover America sometime between 1421 and 1423.

    "In principle, he's (British author Gavin Menzies) right. Before Columbus, Zheng He discovered America and the whole world. But in detail, not precisely... three years difference. I don't think that's a big deal."

    Zheng He commanded a massive fleet, which sailed between 1405 and 1433 at the behest of the emperor during China's Ming Dynasty.

    His mandate was to spread the glory of China to the world and establish trade.