International organizations — Immunity — Attachment and execution — Whether assets of organization liable to attachment to satisfy arbitration award — Discovery of assets — Whether court has jurisdiction to require organization to make full disclosure of its assets — Officials — Immunity — Immunity from suit and legal process for things done or omitted to be done by officials in performance of their functions — Whether conferring immunity from being required to give evidence — Inviolability of archives — Whether order that organization disclose details of its assets inconsistent with inviolability of official archives — The law of England