14. Any contract or instrument which, if entered into or executed by an individual, would not require to be[F2 executed as a deed] may be entered into or executed on behalf of the[F3 Executive] by any person generally or specially authorised by the[F3 Executive] to act for that purpose, and any document purporting to be such a contract or instrument shall be deemed to be such a contract or instrument until the contrary is proved.N.I.