Power to summon persons: authorised excise officers may compel attendance and document production, subject to civil procedure exemptions. A duly empowered Central Excise Officer may summon any person to give evidence or produce specified documents or all documents of a described class; summoned persons must attend in person or by authorised agent, state the truth when examined, and produce required documents. Exemptions under the Code of Civil Procedure apply to attendance requisitions, and such inquiries are treated as judicial proceedings for purposes of penal provisions.