The lawsuit will allege the agencies had "factual and exculpatory evidence that they fraudulently concealed from the family of Malcolm X and the men wrongly convicted of crimes surrounding the assassination of Malcolm X," Crump said in a statement ahead of a news conference.
The announcement of intent to sue comes exactly 58 years since the civil rights leader was shot and killed while speaking at the Audubon Ballroom in Washington Heights.
WATCH: Gil Noble reports on lingering questions in Malcolm X assassination
It follows decades of discussion and debate over a possible connection between Malcolm's death and federal and New York government agencies, including the NYPD, FBI and CIA.
A year and a half ago, the two men convicted of killing Malcolm X were exonerated.