(1) The chief registrar may, as a condition of registration, require the grantor to present for registration an instrument prior to the instrument presented for registration which, in the opinion of the chief registrar, is necessary in order to show on the face of theregister the title of the grantor to execute the instrument.

(2) Where the grantor satisfies the chief registrar as to the existence and purport of a prior instrument and that the instrument is not within the possession, power or control of the grantor, the chief registrar may accept and register, in lieu of the instrument, the documentary evidence of the prior instrument that the chief, registrar considers sufficient