The affixing of the seal of the Commission shall be done and authenticated by the signature of the National Commissioner or such other member authorised by the Council to act for that purpose

A contract or instrument which, if made by a person not being a body corporate, shall not be required to be under seal, may be made or executed by the National Commissioner or by any other officer or staff specifically authorised by the National Commissioner...

A document purporting to be a contract, an instrument, or other document signed or sealed on behalf of the Commission shall be received in evidence and shall, unless the contrary is proved, be presumed, without further proof, to have been so signed and...