Bob Denard, the French soldier-of-fortune whose near mythical involvement in African wars since the 1960s made him one of the world's most famous mercenaries, has died at the age of 78.

He had been suffering from Alzheimer's disease.

Denard, whose death was confirmed by his sister, Georgette Garnier, became legendary for his role in attempting to overthrow regimes in a series of wars during the 1960s and 1970s that accompanied the decolonisation of Africa.

Claiming to have covert support from France for operations meant to retain French influence in its former colonies, he called himself the Pirate of the Republic in a career that began in Congo and ended in the Comoros islands.

His detractors accused him of links to the extreme-right, using the cover of defending French interests for maverick operations that made him feared and hated in Africa.

"Denard was symbolic of the whole ambiguity of relations between the colonisers and the colonies which had became independent," said Bertrand Badie, professor of international relations at Sciences Po university in Paris.

"He's also seen a bit as the inventor of private armies."

Denard made his reputation as a mercenary in Congo, where his ruthless efficiency when faced with poorly equipped, poorly trained African troops earned the nickname for his band of former European soldiers as "les affreux" (the frightful ones).

He was part of a commando team that rescued white civilians encircled by rebels in 1964 in what was then known as Stanleyville in Congo, a raid which formed the basis of the film, The Wild Geese.

Later Denard drifted on to other wars in North Yemen, Biafra and Angola, before fixing on the country that would become the target of most of his later operations - the Comoros islands.

It was in this Indian Ocean archipelago that he became involved in four coups and coup attempts since the islands became independent from France in 1975.

Senior Comoros military commander Abdallah Gamil said Denard had been admitted to a hospital in Paris late on Saturday. "About 40 minutes later, one of Bob's close friends told me he had died," he said.

Denard was sentenced by a Paris court in July for his part in a 1995 coup in Comoros.

He and others were charged with overthrowing Comoros President Mohammed Djohar in September 1995, when they put opposition leaders Mohammed Taki and Said-Ali Kemal in power.

The court sentenced Denard to four years in jail but ordered three of them suspended. A separate sentencing judge was supposed to decide whether the ailing Denard would serve time behind bars.

Many Comorians were bitter Denard did not face justice on the Indian Ocean archipelago.

"This man sullied our history," said Abdou Soule Elbak, former president of Grande Comore.

"I regret he was not made to answer to all the crimes he committed in our country, the murders and the torture which he was guilty of," said Moustoifa Said Cheikh, leader of the Democratic Front party.

Born in the Bordeaux region of France in 1929 as Gilbert Bourgeaud, Denard served in the French Marine Commandos in the early 1950s before entering the colonial police in pre-independence Morocco and Algeria.

A Congolese businessman who knew Denard in the early 1960s in Congo described him as a fearless man who came only to fight.

"He was above all an adventurer," Kasuku Wa Ngeyo told Reuters in the Congolese town of Goma. "At the time, there were people fascinated by hunting. But he was fascinated by war."

Reuters