star chamber

n. [ So called (as conjectured by Blackstone) from being held in a room at the Exchequer where the chests containing certain Jewish contracts and obligations called starrs (from the Heb. shetar, pron. shtar) were kept; or from the stars with which the ceiling is supposed to have been decorated. ] 1. (Eng. Hist.) An ancient high court exercising jurisdiction in certain cases, mainly criminal, which sat without the intervention of a jury. It consisted of the king's council, or of the privy council only with the addition of certain judges. It could proceed on mere rumor or examine witnesses; it could apply torture. It was abolished by the Long Parliament in 1641. Encyc. Brit. [ 1913 Webster ]

2. Hence: (Metaphorical) Any court, committee, or other tribunal which exercises arbitrary and unaccountable power, or uses unfair or illegal methods, in investigation or judgment of persons. [ PJC ]