Sovereign immunity — Foreign State and State-owned companies — Land survey company nationalized and integrated into foreign State — Sub-contract concluded before nationalization — Action by sub-contractor for damages — Acts iure imperii and iure gestionis — Whether restrictive or absolute theory of sovereign immunity to be applied — Attachment of property of foreign State

International law in general — Relation to municipal law — Whether international law part of the law of South Africa — Principles of international law conflicting with South African legislation or with common law

Recognition — Of States and governments — Whether exclusively within the prerogative of the Executive — Conclusive character of Executive certificate — Practice of the courts — The law of South Africa