Famed explorer Christopher Columbus was likely Spanish and Jewish, according to a new genetic study by Spanish scientists that aims to shed light on a centuries-old mystery.

Scientists believe the explorer, whose 1492 expedition across the Atlantic changed the course of world history, was probably born in Western Europe, possibly in the city of Valencia.

They assume that he hid his Jewish identity or converted to Catholicism to avoid religious persecution.

The study of the DNA contradicts the traditional theory, questioned by many historians, that the discoverer was an Italian from Genoa.

Columbus led an expedition supported by the Catholic Monarchs of Spain to establish a new route to Asia – but instead he reached the Caribbean.

His arrival there marked the beginning of a period of European contact with the Americas that would lead to conquest and settlement – and the deaths of many millions of indigenous peoples from disease and war.

Countries have been arguing about the discoverer's origins for years, and many claim he is one of their own.

There were an estimated 25 conflicting theories about his birthplace, including Poland, Great Britain, Greece, Portugal, Hungary and Scandinavia.

These new findings are based on more than two decades of research.

The study began in 2003 when José Antonio Lorente, professor of forensic medicine at the University of Granada, and historian Marcial Castro exhumed what were believed to be Columbus' remains from Seville Cathedral.

Columbus died in the Spanish city of Valladolid in 1506, but wanted to be buried on the Caribbean island of Hispaniola. His remains were transferred there in 1542, but centuries later they were transferred to Cuba before finally being buried in Seville.

The researchers also took DNA samples from the tomb and from the bones of Columbus' son Hernando and his brother Diego.

Since then, scientists have been comparing this genetic information with that of historical figures and the discoverer's relatives to solve the mystery.

The previously widely accepted theory was that Columbus was born in Genoa in 1451 to a family of wool weavers.

But they now believe he lived in Spain – probably Valencia – and was Jewish. They believe he hid his origins to avoid persecution.

About 300,000 observant Jews lived in Spain before they were ordered, along with Muslims, to either convert to Catholicism or leave the country in 1492, the year Columbus landed in the Americas.

Professor Lorente announced the results of the study in the television documentary “Columbus DNA: His True Origin,” saying they were “almost absolutely reliable.”

The program, which aired on Spain's national broadcaster RTVE on Saturday evening, coincided with Spain's National Day.

The day celebrates the explorer's arrival on the American continent.