Power to take evidence: Commissioners may exercise court like powers to summon witnesses and impound documents in tax proceedings. The Commissioner and officers determining objections have the same powers as a civil court to summon and examine persons on oath, compel production of accounts and documents, and issue commissions for witness examination, with proceedings treated as judicial for purposes of criminal provisions on false evidence. Subject to rules, the Commissioner or such officer may impound and retain books of account and other documents produced in proceedings until those proceedings conclude, provided that written reasons for any impoundment are recorded.