International organizations — Officials — Immunity — Scope — Whether officials liable to expulsion from receiving State — Officials not assimilated to diplomatic agents — Agreement on the Privileges and Immunities of the United Nations, 1946, Article V, Sections 15 and 16 — Immunity limited to acts performed in an official capacity — Exemption from immigration restrictions and alien registration — Whether including immunity from expulsion

Aliens — Expulsion — Officials of international organizations — International officials not assimilated to diplomatic agents — Whether subject to expulsion in absence of express treaty provisions to the contrary — Inherent power of receiving State to secure order in its territory — The law of Switzerland