The Removal Squad is a clean-up crew of the Space Pirates mentioned in a scan in Research Lab Aether in the Phendrana Drifts during Metroid Prime. They were requested after a stasis tank (potentially a Xenome Containment Unit containing a Tallon Metroid) was contaminated beyond safety standards. Whether Pirate groups on other missions to planets, such as Zebes or Aether also had Removal Squads is unknown, but possible.
"Stasis tank B11B contaminated beyond acceptable safety standards. Removal Squad requested."