"SECTION 220. Form and Mode of Proceeding in Actions Arising under this Code. - Civil and criminal actions and proceedings instituted in behalf of the Government under the authority of this Code or other law enforced by the Bureau of Internal Revenue shall be brought in the name of the Government of the Philippines and shall be conducted by legal officers of the Bureau of Internal Revenue but no civil or criminal action for the recovery of taxes or the enforcement of any fine, penalty or forfeiture under this Code shall be filed in court without the approval of the Commissioner.

"SECTION 221. Remedy for Enforcement of Statutory Penal Provisions. - The remedy for enforcement of statutory penalties of all sorts shall be by criminal or civil action, as the particular situation may require, subject to the approval of the Commissioner.

"SECTION 222. Exceptions as to Period of Limitation of Assessment and Collection of Taxes. -

"(a) In the case of a false or fraudulent return with intent to evade tax or of failure to file a return, the tax may be assessed, or a proceeding in court for the collection of such tax may be filed without assessment, at any time within ten (10) years after the discovery of the falsity, fraud or omission: Provided, That in a fraud assessment which has become final and executory, the fact of fraud shall be judicially taken cognizance of in the civil or criminal action for the collection thereof.

"(b) If before the expiration of the time prescribed in Section 203 for the assessment of the tax, both the Commissioner and the taxpayer have agreed in writing to its assessment after such time, the tax may be assessed within the period agreed upon. The period so agreed upon may be extended by subsequent written agreement made before the expiration of the period previously agreed upon.

"(c) Any internal revenue tax which has been assessed within the period of limitation as prescribed in paragraph (a) hereof may be collected by distraint or levy or by a proceeding in court within five (5) years following the assessment of the tax.

"(d) Any internal revenue tax, which has been assessed within the period agreed upon as provided in paragraph (b) hereinabove, may be collected by distraint or levy or by a proceeding in court within the period agreed upon in writing before the expiration of the five (5)-year period. The period so agreed upon may be extended by subsequent written agreements made before the expiration of the period previously agreed upon.

"(e) Provided, however, That nothing in the immediately preceding Section and paragraph (a) hereof shall be construed to authorize the examination and investigation or inquiry into any tax return filed in accordance with the provisions of any tax amnesty law or decree.