PORT-AU-PRINCE (REUTERS) - Max Gesner Beauvoir, the"Ati" or supreme leader of voodoo, Haiti's traditional Afro-Caribbean religion, died Saturday afternoon, aged 79, according to his family.

President Michel Martelly took to Twitter to express his sympathies, saying Beauvoir's death was "a great loss for the country".

Mr Beauvoir left Haiti in the 1950s to study chemistry in New York City. After going on to the Sorbonne in Paris, he returned to the United States where he worked as a chemist for private companies.

A New York Times profile of Mr Beauvoir said he returned to Haiti in the 1970s where his dying grandfather urged him into a life as an houngan, or voodoo priest.

Sometimes misrepresented in Hollywood as a black magic cult, voodoo is widely respected and revered by millions of Haitians. It is closely identified with the nation's history of slavery, and its struggle for independence from French colonial rule.

"Voodoo heals the mind, soul and body. The soul is what we are, which controls everything, all our actions and mind," Mr Beauvoir told the Thomson Reuters Foundation in a recent interview.

At a voodoo temple inside his coral stone-walled home outside the capital Port-a-Prince, Mr Beauvoir made offerings, including bottled drinks, cows, goats and chickens, to religious spirits.

"Voodoo is the soul of the Haitian people and nothing can be done without that cultural basis. It is a way of life," he said.

Voodoo has been practiced since the 18th century, but it only won recognition as an official religion in 2003 under President Jean-Bertrand Aristide.

Around 70 per cent of Haitians are believed to practice voodoo.

Mr Beauvoir estimated there were more than 60,000 voodoo priests across Haiti, many living in rural communities.