(1) Where a prosecution for a prescribed taxation offence is instituted by a person in the official name of the Commissioner, the prosecution shall be presumed, unless the contrary is proved, to have been instituted with the authority of the Commissioner.
(2) In a prosecution for a prescribed taxation offence, the mere production of an instrument, telegram or copy of a telex message purporting to have been issued or sent by the Commissioner, a Second Commissioner or a Deputy Commissioner and purporting to notify a person that the person is authorized by the Commissioner to institute the prosecution, to institute prosecutions for a class of prescribed taxation offences in which the prescribed taxation offence is included or to institute prosecutions for any prescribed taxation offence is conclusive evidence of the authority of the person to institute the prosecution on behalf of, and in the official name of, the Commissioner.