Statements made or documents produced by or on behalf of a person shall not be inadmissable in any such proceedings as are mentioned in subsection (2) below by reason only that it has been drawn to his attention —
(a) that where serious tax fraud has been committed the Board may accept a money settlement and that the Board will accept such a settlement, and will not pursue a criminal prosecution, if he makes a full confession of all tax irregularities, or
(b) that the extent to which he is helpful and volunteers information is a factor that will be taken into account in determining the amount of any penalty,
and that he was or may have been induced thereby to make the statements or produce the documents.
The proceedings mentioned in subsection (1) above are—
(a) any criminal proceedings against the person in question for any form of fraudulent conduct in connection with or in relation to tax, and
(b) any proceedings against him for the recovery of any tax due from him and
(c) any proceedings for a penalty or on appeal against the determination of a penalty.