Italy, France, Portugal and even Scotland are among those who have claimed Christopher Columbus as their own over the years, citing a range of spurious links.

By Fiona Govan in Madrid

But American researchers say the mystery over the explorer's true origins has finally been solved after a thorough investigation of his writings.

A study of the language used in the official records and letters of the Great Navigator apparently proves he hailed from the Kingdom of Aragon in northeastern Spain and his mother tongue was Catalan.

Since his death in 1506 debate has raged over the true nationality of the man credited with discovering the Americas.

It was widely believed that he was the son of a weaver born in the Italian port of Genoa, but over the centuries he has been claimed as a native son of Greece, Catalonia, Portugal, Corsica, France and even Poland.

According to one theory, he may have been Jewish and another more recent account traced his origins to Scotland.

But a linguistic professor at Georgetown University in Washington has published new findings following an exhaustive study of documents written in his hand.

Estelle Irizarry studied his language and grammar and concluded that Columbus was a Catalan speaking man from the Kingdom of Aragon, an inland region of north-eastern Spain at the foot of the Pyrenees.

The findings published this month in a new book "The DNA of the writings of Columbus" explain that although he wrote in Castilian it was clearly not his first language and his origins can be pinpointed to the Aragon region because of the grammar and the way he constructed sentences.

"He didn't express him correctly in any written language," said the professor. "His Spanish was notoriously incorrect yet at the same time efficient, poetic and eloquent."

A scientific project launched three years ago to discover his true origins using DNA comparisons between his family and possible descendants has so far failed to provide conclusive results.

A team of scientists took samples from the tomb of Columbus in Seville and from bones belonging to his brother and son and compared them to the genetic make-up of hundreds of people living across Europe with surnames believed to be modern day variants of Columbus.

Swabs were taken from the cheeks of Colom's in Catalonia, Colombo's in Italy and even members of the deposed Portuguese royal family, who argue that Columbus was the product of an extramarital affair involving a Portuguese prince.

Scientists had hoped to establish a common ancestor using standard Y-chromosome tests but they have yet to find a link.

They study may be in vain, however, as there is evidence to suggest that Columbus, who first crossed the Atlantic in 1492, may have adopted his surname later in life to disguise his true origins.

One theory claims that he once worked for a pirate called Vincenzo Columbus, and adopted that name in order not to embarrass his relations with his new profession.

Columbus himself, when asked about his origins, used to shrug off the questions. "Vine de nada" – "I came from nothing", he said.