Detention of goods under Customs law: custodians may claim storage and demurrage charges despite Customs detention. Detention under the Customs Act prevents owners from removing detained goods without permission while investigations proceed; custodians and shipping lines charge warehousing, demurrage and container detention fees for custody periods. Customs may issue detention certificates and recommend remission, but custodians are not compelled to waive charges; judicial authorities have recognised custodians' entitlement to recover such charges even where Customs detention is later held improper.