The federal government has reopened the investigation into the lynching murder of Emmett Till.

The Justice Department told Congress in a March report that the case would be reopened based on "new information," although a cousin of the slain teen said she was not aware of the development until she was contacted by reporters, reported the Associated Press.

The 1955 murder of the black 14-year-old shocked the world and helped inspire the civil rights movement.

The federal report is sent annually to lawmakers under legislation bearing Till's name, and this year's report does not describe the new information that triggered the additional investigation.

However, the report came out after the publication of “The Blood of Emmett Till,” a book that reveals a key figure in the case admitted she had lied about the events that led to the boy's murder.

Carolyn Donham, now 84 years old, admitted to author Timothy Tyson that she had lied during her testimony about Till grabbing her, whistling and making sexual advances at a store owned by her husband -- who was charged with the teen's murder.

Donham’s then-husband Roy Bryant and his half-brother J.W. Milam were charged with murder but later acquitted in Till's slaying.

The men later confessed to killing the boy in a magazine interview but weren't retried, and both men are now dead.