Photocurrent spectroscopy is used to investigate the properties of the CdHgTe (CMT)/anodic oxide /electrolyte junction. The anodic oxide growth follows the high‐field growth mechanism and the positive photocurrent response is found to originate from a thin layer close to the CMT/anodic oxide interface. The spectral response of this photocurrent indicates that the oxide is amorphous with a band gap of 2.8 eV. This value is considerably lower than has been previously reported. Electron photoemission also occurs at the CMT/anodic oxide interface, with an apparent threshold energy of ∼2.08 eV.