18. Except in so far as in any particular case any privilege or immunity is waived by the Council, any expert (other than officers of the Organization) employed on a mission on behalf of the Organization shall, while present in the United Kingdom for the discharge of his duties, enjoy:—
(a)immunity from suit and legal process in respect of things done or omitted to be done by him in the exercise of his official functions for the Organization;
(b)inviolability for all papers and documents relating to the work on which he is engaged for the Organization;
(c)unless he is a citizen of the United Kingdom and Colonies, the like immunity from personal arrest and detention and from seizure of his personal baggage as is accorded to a diplomatic agent; and
(d)unless he is a citizen of the United Kingdom and Colonies, the like exemption and privileges in respect of his personal baggage as in accordance with Article 36 of the 1961 Convention Articles are accorded to a diplomatic agent.