lovlig anholdelse eller anden frihedsberøvelse af en person for at hindre ham i uretmæssigt at trænge ind i landet eller af en person, mod hvem der tages skridt til udvisning eller udlevering.  
the lawful arrest or detention of a person to prevent his effecting an unauthorised entry into the country or of a person against whom action is being taken with a view to deportation or extradition.  