5.—(1) Except in so far as in any particular case such immunity is waived by the Court, persons participating in proceedings shall have–
(a)in respect of words written or spoken and documents or other evidence submitted by them before or to the Court (other than where such words, documents or evidence or any part thereof are communicated by them or on their behalf outside the Court), the like immunity from suit and legal process as is accorded to or in respect of the head of a diplomatic mission; and
(b)while passing in transit through the United Kingdom during their journeys to and from the proceedings, or while in the United Kingdom for the purpose of such proceedings there, immunity from criminal proceedings and (other than for the purpose of detaining a person who has escaped from legal custody) from personal arrest in respect of acts or convictions prior to the commencement of the journey.
(2) The immunity accorded by sub-paragraph (1)(b) is effective only if the presence of the persons at the proceedings has been authorised in advance by the Court and 15 days have not elapsed from the date when their presence is no longer required by the Court.