Back in 1966, the FBI was keeping watch over Muhammad Ali. They were investigating the Nation of Islam and were keen to keep an eye on him after his speech at a Miami mosque.
This is all according to newly released FBI documents that were put up on the FBI website.
Ali died in June at the age of 74. All the big names came out to honor him after his passing, even Bill Clinton was at his funeral.
The FBI has a long history of monitoring public figures. They closely watched Martin Luther King Jr as well as John Lennon in the 60's and 70's.
See the iconic athlete throughout his career:
The documents released about Ali were classified for years. They were only released after conservative group Judicial Watch sued them for access to the papers.
In the documents, there are requests for agents to monitor his divorce from his first wife. They claimed this was a "lead."
"The Miami (FBI) office is requested to follow the divorce action between Cassius and Sonja Clay with particular emphasis being placed on any NOI (Nation of Islam) implication being brought into this matter," according to one document.
A different document covers him speaking at a mosque in 1966. In his speech, he discussed efforts to strip him of his boxing title and he blamed the "white man."
The biggest controversy concerned his conscientious objector status during the Vietnam War. He was stripped of his boxing title in 1967 for his refusal to go to war.
The FBI documents stress that Ali was never under investigation personally.
Look back at Ali's funeral: