Social presence has two opposing effects on human corruption: the collaborative and contagious nature of another person's presence can cause people to behave in a more corrupt manner. In contrast, the monitoring nature of another person's presence can decrease corruption. We hypothesize that a robot's presence can provide the best of both worlds: Decreasing corruption by providing a monitoring presence, without increasing it by collusion. We describe an experimental study currently underway that examines this hypothesis, and report on initial findings from pilot runs of our experimental protocol.