All cigarettes with respect to the storage or use of which the tax imposed herein is not paid, as herein provided, are declared to be contraband goods and may be seized by the commissioner or his agents or employees, or by any peace officer of this state when directed by the commissioner to do so, without a warrant, provided nothing herein shall be construed to require the commissioner to confiscate unstamped cigarettes when he has reason to believe that the owner thereof is not wilfully or intentionally evading the tax imposed by this part.