Malcolm X rose to prominence as the national spokesman of the Nation of Islam, an African-American Muslim group that espoused Black separatism.
He spent over a decade with the group before becoming disillusioned, publicly breaking with it in 1964 and moderating some of his earlier views on racial separation, angering some Nation of Islam members and drawing death threats.
Malcolm X's family plans to sue the FBI, CIA and New York City police for $100m (£82.6m) in damages over the assassination of the US civil rights activist exactly 58 years ago on Tuesday.
His daughter Ilyasah Shabazz has accused several federal and New York government organisations of fraudulently concealing evidence, saying that they "conspired to and executed their plan to assassinate Malcolm X".
"For years, our family has fought for the truth to come to light concerning his murder," Ms Shabazz said at a news conference at the site of her father's assassination, now a memorial to Malcolm X. 219
