81. When a fiscal law or a regulation made under such law obliges a person to file a return, statement, answer or certificate, an affidavit of a functionary of the Ministère du Revenu attesting that he is entrusted with the appropriate registers and after making a careful examination of it,(a) he was unable to ascertain that the return, statement, answer or certificate, as the case may be, was filed by the said person, shall be primafacie proof that no return, statement, answer or certificate, as the case may be, has been filed by such person; or
(b) he has ascertained that the return, statement, answer or certificate was filed on a designated day shall be primafacie proof that the return, statement, answer or certificate was filed on the date indicated and not previously.