Any payments made by the employer to the injured employee during the period of his disability, or to his dependents, which by the terms of this title were not due and payable when made, may, subject to the approval of the Commission, be deducted from the amount to be paid as compensation, provided that, in the case of disability, such deductions shall be made by reducing the amount of the weekly payment in an amount not to exceed one-fourth of the amount of the weekly payment for as long as is necessary for the employer to recover his voluntary payment. However, any payments made to an injured employee under the Longshore and Harbor Workers’ Compensation Act of 1927, as amended, 33 U.S.C. § 901 et seq., may be deducted in full from the amount to be paid as compensation for the same injury under this title.