During the present war, whenever there is reasonable cause to believe that the manifest or the additional statements under oath required by section 4313 of this title are false or that any vessel, domestic or foreign, is about to carry out of the United States any property to or for the account or benefit of an enemy, or ally of enemy, or any property or person whose export, taking out, or transport will be in violation of law, the collector of customs for the district in which such vessel is located is authorized and empowered subject to review by the President to refuse clearance to any such vessel, domestic or foreign, for which clearance is required by law, and by formal notice served upon the owners, master, or person or persons in command or charge of any domestic vessel for which clearance is not required by law, to forbid the departure of such vessel from the port, and it shall thereupon be unlawful for such vessel to depart.