Section 17. Specifications governing the manner and time of such physical examinations shall be promulgated by the department of public health. Said department shall prescribe the medical records to be kept, shall require such laboratory or other diagnostic aids to be used as in its judgment are expedient, and shall forward to the commissioner statements of the results of all such examinations, together with recommendations relative thereto. For the purpose of obtaining further information relative to such prisoners the commissioner may cause inquiry to be made of court physicians and psychiatrists, probation officers and district attorneys, who have made examinations or investigations of such prisoners prior to conviction or who have prosecuted them, and such physicians, psychiatrists and probation officers shall furnish to the commissioner when requested all pertinent information in their possession. The commissioner may cause such further inquiry to be made relative to the offences committed by such prisoners and their past history and environment as he may deem necessary. He shall cause records to be made of such examinations and investigations.