I have been asked to reply. I am aware that complaints have been made as to the detention of vessels at contraband control bases. The matter has received my constant attention, and the authorities concerned are fully alive to the importance of avoiding any unnecessary delay. Lengthy detention of ships has occurred principally where vessels with large mixed cargoes have arrived in British waters without advance copies of their manifests having been furnished, and containing many important consignments as to the ultimate destination of which proper inquiries were essential. The recent introduction of the Navicert system will enable the necessary inquiries to be made before consignments are shipped from certain overseas exporting countries, and when the advantages of this system have been fully appreciated by exporters and shipowners, the delays caused to shipping by our contraband control should be reduced to a minimum.