Abstract: A security locking device for releasably locking gates, doors and the like is made up of a bolt receiver and a locking bolt assembly, the locking bolt assembly including a slidable locking bolt which extends through a mounting tube for slidable movement between an extended locking position in the bolt receiver and a retracted, unlocked position removed from the receiver, and a locking wedge extends through slots in the mounting tube and locking bolt to retain the locking bolt in the locking position, the wedge in turn being locked securely in position by a locking member within the mounting tube. Mounting brackets are provided for tamper-proof attachment of the bolt receiver and locking bolt assembly to the respective members to be releasably locked.