"SECTION 13. Authority of a Revenue Officer. - Subject to the rules and regulations to be prescribed by the Secretary of Finance, upon recommendation of the Commissioner, a Revenue Officer assigned to perform assessment functions in any district may, pursuant to a Letter of Authority issued by the Revenue Regional Director, examine taxpayers within the jurisdiction of the district in order to collect the correct amount of tax, or to recommend the assessment of any deficiency tax due in the same manner that the said acts could have been performed by the Revenue Regional Director himself.

"SECTION 14. Authority of Officers to Administer Oaths and Take Testimony. - The Commissioner, Deputy Commissioners, Service Chiefs, Assistant Service Chiefs, Revenue Regional Directors, Assistant Revenue Regional Directors, Chiefs and Assistant Chiefs of Divisions, Revenue District Officers, special deputies of the Commissioner, internal revenue officers and any other employee of the Bureau thereunto especially deputized by the Commissioner shall have the power to administer oaths and to take testimony in any official matter or investigation conducted by them regarding matters within the jurisdiction of the Bureau.

"SECTION 15. Authority of Internal Revenue Officers to Make Arrests and Seizures. - The Commissioner, the Deputy Commissioners, the Revenue Regional Directors, the Revenue District Officers and other internal revenue officers shall have authority to make arrests and seizures for the violation of any penal law, rule or regulation administered by the Bureau of Internal Revenue. Any person so arrested shall be forthwith brought before a court, there to be dealt with according to law.