Was Leonardo da Vinci's mother a Chinese slave? That astounding theory is being put forward by a Hong Kong-based historian and novelist who has spent the last two years piecing documents together to connect the dots. And it is not the only link between the mysterious artist and thinker and this part of the world, according to Angelo Paratico. The Italian who painted the Mona Lisa and The Last Supper might also have inspired Macau's most iconic landmark. Paratico is finishing a non-fiction book entitled Leonardo Da Vinci: a Chinese scholar lost in Renaissance Italy which he hopes to publish next year. In the work, he traces ties between Da Vinci and the Far East. A Hong Kong resident of more than 20 years, the Italian has also written 500 years of Italians in Hong Kong & Macau . On his latest subject, Paratico says he is "sure up to a point that Leonardo's mother was from the Orient, but to make her an oriental Chinese, we need to use a deductive method". It is widely accepted that the artist's father was a notary. Very little is known, however, about his mother Caterina, with some believing she was a local peasant. But Paratico supports a different theory. "One wealthy client of Leonardo's father had a slave called Caterina. After 1452, Leonardo's date of birth, she disappeared from the documents. She was no longer working there." Caterina was taken to Vinci, about 20 miles from Florence, where she gave birth. That move was made, Paratico believes, because a relationship with a slave was seen as improper. Theories that Da Vinci's mother might have been a Middle Eastern slave surfaced with papers discovered in 2002. Then in 2007, University of Chieti researchers, using Da Vinci's complete fingerprints, said he might have been an Arab. The following year, Italian research suggested his mother was a slave. To Vitor Teixeira, art historian and assistant professor at the University of St Joseph in Macau, the Middle Eastern theory is more acceptable than the "far-fetched" idea that Caterina was from China, in view of the slaves' origin at the time and also Da Vinci's facial features. So why does Paratico think Caterina was in fact Oriental? "During the Renaissance, countries like Italy and Spain were full of oriental slaves," he says. Paratico also points to other indications of Chinese ancestry, "for instance, the fact he was writing with his left hand from left to right … and he was also a vegetarian, which was not common" among Europeans. Chinese characteristics can be found in Da Vinci's work, Paratico adds. " Mona Lisa is probably a portrait of his mother, as Sigmund Freud said in 1910. On the back of Mona Lisa , there is a Chinese landscape and even her face looks Chinese." Only DNA analysis, using samples from relatives buried in Florence, can solve the mystery, he says. But Paratico does not rest there. He believes Macau's Ruins of St Paul might have been inspired by a Da Vinci sketch. A disciple of Da Vinci, painter Francesco Melzi inherited most of his sketches. And Paratico believes there was a good chance that Melzi had shown the draft to Carlo Spinola, who is believed to have directed the church project. But he accepts there is no proof. Researchers are sceptical about Paratico's ideas. "I respect his theory and it's an interesting proposition, but I don't think that the facade was inspired by a Leonardo Da Vinci sketch," Macau Ricci Institute art historian Cesar Guillen Nunez says. An architect and assistant professor at the University of St Joseph, Francisco Vizeu Pinheiro, says Paratico is "jumping quickly to conclusions since there's no concrete evidence".