The Federation Bureau is an organization that founded the Federation Police Force, first mentioned in the instruction manual for Metroid. In the Metroid Manga, Chairman Vogl pushed them to side with him over Chairman Keaton to enlarge and unite the Police. In the Super Metroid comic, there is a spacecraft called the Federation Bureau Headquarters, which appears to be the base of operations for the bureau.
"The Federation Bureau and the Federation Police called together warriors known for their great courage and sent them to do battle with the pirates. These great warriors were called "space hunters." They received large rewards when they captured pirates, and made their living as space bounty hunters."