Subsequent sentence of corrective training, preventive detention or imprisonment
31.—(1) If any person while released on licence under regulation 27, or after he is recalled to a prison under regulation 29, is sentenced by a court to corrective training or preventive detention, the sentence by virtue of which he is on licence or has been recalled shall cease to have effect.
(2) If any person while released on licence under regulation 27, or after he is recalled to a prison under regulation 29, is sentenced to imprisonment, any period for which he is imprisoned under that sentence shall count as part of the period for which he is liable to detention under the original sentence.