We present the first experimental evidence of fast hot carrier photosignal over HgCdTe p-n junction induced by high intensity CO2 laser pulses. The signal polarity is opposite to that of an ordinary photovoltaic emf The hot carrier photosignal manifests itself when the ordinary photovoltage gets saturated or the junction is forward-biased. The dependencies of the photosignal on laser intensity and applied bias voltage are studied.