State immunity — Head of State — Scope of immunity from criminal jurisdiction — Whether absolute — Whether differing from scope of immunity from civil jurisdiction — Waiver — Conditions — Rules of customary international law — Vienna Convention on Diplomatic Relations, 1961, Article 32 — Application to head of State by analogy

State immunity — Head of State — Former head of State — Whether entitled to immunity from the criminal jurisdiction of courts in other States — Whether immunity subsisting in relation to acts performed in exercise of functions — Rules of customary international law — Vienna Convention on Diplomatic Relations, 1961, Article 39 — Application to head of State by analogy — The law of Switzerland