An anti-cheating device for a gaming machine which prevents or detects the insertion of a cheating device through the coin slot or a coin chute. The device includes a spring biased sheath which acts to cover the needle before and after use. A displayed state estimation section receives the map data acquired by the map data acquisition section, and estimates a displayed state of the displayed object based on the map data. The housing may be a clamshell-like, two part housing and may have an internal chamber extending between two cable seal members which provide a seal between opposite end ports and the cable at opposite ends of the chamber.