The militant black group was immediately blamed for the assassination of Malcolm X, was shot at the Audubon Ballroom in Harlem, on February 21, 1965.

He had become its key spokesman, but fell out with the organisation when he started preaching a more inclusive line after a visit to Mecca.

Aziz and two other men were jailed for the shooting.

Among Aziz's new duties will be organising the paramilitary wing, known as Fruit of Islam.

In his famous interview with journalist Alex Haley in Playboy magazine, Malcolm X described Fruit of Islam as a "police force of judo-trained athletes" - but it has been largely inactive since his death.

Malcolm X was born in 1925 in Omaha, Nebraska. Christened Malcolm Little, he said his light skin was the result of his grandmother having been raped by a white man.

As a young man, he turned to crime and spent 77 months in prison himself. There he converted to Islam, in particular the radical beliefs of Elijah Muhammad.

He took the surname "X" as a symbol of all the black slaves who lost their names when they were brought to the Americas.

He later adopted the Islamic name of Al-Hajj Malik El-Shabazz as he became a public figure proselytising fiercely along the lines set out by Muhammad.

For a time, Malcolm X insisted on referring to all white people as "devils". But his visit to Mecca led to a profound change.

Afterwards, he wrote: "Never have I witnessed such sincere hospitality and overwhelming spirit of true brotherhood as is practised by people of all colours and races here in this ancient Holy Land, the home of Abraham, Muhammad and all the other Prophets of the Holy Scriptures. For the past week, I have been utterly speechless and spellbound by the graciousness I see displayed all around me by people of all colours."

It is this second conversion that many, including director Spike Lee in his film Malcolm X, attribute to be the key cause of his murder.