I have a cheating question?

No, not that kind of cheating....We have a chess game at work and two coworkers have been played several games against each other. All the games have been won by the same person. Thing is, the person that won has been using a program that calculates each move in the game to win.

How should I secretly let the other person know they are / may be cheating? Small company and the cheater is the VP.