In order to characterize systematically, and in detail, the defects in cadmium telluride (CdTe) a study was performed based on the kinetics of γ-ray induced damage in material kept at room temperature. A wide range of defect levels, ranging from shallow to mid-gap levels, was investigated by using photo-induced current transient spectroscopy (PICTS) and thermally stimulated current (TSC) techniques. It appears that γ-ray irradiation does not introduce any new levels in addition to those pre-existing in the as grown material, but large changes in their concentration are observed. The kinetics of this change depend on the nature of the sample. However, for all samples, the evolution of the material follows a definite pattern. In all materials, a constant decrease in the 0.15 eV band is observed, whereas a constant increase of the 0.30 eV band is found. The near mid-gap levels show a more complicated behaviour. Based on this study, several conclusions have been drawn on the generation of defects in CdTe and their nature and origin. The role played by chlorine, used generally for compensation in semi-insulating crystals, is considered, in particular.