If the sheriff is in charge of a jail, prison or place of detention, the sheriff shall receive allowances for the custody, care and maintenance of prisoners and inmates as may be fixed by the courts or official boards of the respective counties having supervision of the institutions, or as the courts or boards may approve, upon submitted bills to be paid by the county in addition to compensation for services fixed by statute, by a court or by official board authorized to fix the compensation.
42 P.S. § 21112