More evidence has been unearthed which suggests that Chinese Ming dynasty explorer Zheng He might have founded America decades before Christopher Columbus did in the late 15th century.

A seven-centimetre-wide brass medal, complete with Ming dynasty inscriptions and dug up kilometres inland from the North Carolina coast, was recently unveiled for the first time.

This followed the unveiling of a map six months ago by Beijing lawyer Liu Gang, which he claimed is a copy of an A.D. 1418 original drawn up by Chinese explorers.

The six-Chinese-character inscription, “Da Ming Xuan De Wei Ci,” on the medal translates into “Awarded by Xuan De of Great Ming.” It refers to the period between 1426 and 1435, the reign of Emperor Xuan Zong - long before Columbus landed in the New World in 1492.

This, claimed the medal's owner Lee Siu Leung, ties in with the fact that Xuan Zong had, in 1430, commissioned Admiral Zheng to embark on his last voyage to announce his accession to the throne to foreign nations.

“Such a medal represented the highest authority of the emperor and was only delivered by a diplomat like Zheng He or his deputy,” the biochemist and former associate director of the Hong Kong Institute of Biotechnology told media.

He said he bought the medal from “someone who lived in the area where it was found.”

He would not reveal the cost, saying only that he paid much less than the C$560 Liu did for his map.

Ironically, Lee lives in Columbus, Ohio - named after the founder of America. “I do not think they would rename the place 'Zheng He',” he quipped.

Historian Gavin Menzies, author of the controversial book 1421: The Year China Discovered The World, told The Straits Times that the medal, if verified, would give more support to his theories.

“Mr Lee had been my critic for three years so I was naturally overjoyed when I saw the medal,” said the ex-submarine captain, whose work has been exhibited in Singapore. His book is used as a textbook in several US universities.

“We'll put pictures and details on our website and see what other experts have to say.” Menzies felt, however, that the surfacing of more such findings could be compelling enough for a rewrite of the history books.

“I'm confident that within two years, the US could well change its mind to say that Zheng He, and not Columbus, founded America,” he said.

Lee admitted that the medal could have been “robbed by or exchanged with Europeans or native American Indians” resulting in it being found buried inland in America.

“But there is other evidence that could not have come from a third party,” he noted, citing the similarity between pottery styles of the American Indians and Ming dynasty.

Also, he added, the Cherokee term for porcelain is “unaker” (pronounced oo-naker) while in southern Chinese dialects such as Cantonese, it is “uk-nake”(ork-nai).

They were also the only natives to have a flag depicting the Big Dipper constellation - which historically represented Chinese emperors. Lee said this was amazing, considering that they were so backward that they did not even have a language of their own.