In the modern era, robots have become an integral part of human life. In a world where humans and robots need to coexist, it is important to evolve more natural and easy communication mechanisms for human-machine interaction. The communication mechanism needs to be 'easy' more for humans, than machines. One such mechanism can be developed by using natural gestures of the humans. In this paper, a prototype silent spybot is developed that operates by processing the gesture commands signal. The prototype uses video processing with object tracking algorithm to understand the gesture commands. The spybot is programmed to interpret the gesture command signal and navigate according to hand gestures, sensed by a video camera operating within a short range. The gesture commands can be used for controlling the spybot's functions such as movement of the robot, or other operations of the robot, silently. Performance evaluation is carried out through various environments, with encouraging results. As a possible application, a spy robot that captures images from target places silently and sends the spied data to a host computer, is also demonstrated.