State immunity — Attachment and execution — Embassy bank account — Judgment creditor seeking to levy execution against foreign State by attachment of bank account — Principles of international law governing immunity of embassy funds from enforcement jurisdiction of receiving State — Whether execution permissible only if account used exclusively for non-sovereign purposes.

Relationship of international law and municipal law — Executive statements — Certificate of foreign embassy that funds in use for sovereign functions — Note issued by Ministry of Foreign Affairs that such funds not subject to attachment

Diplomatic relations — Immunity — Embassy bank account — Account in use for meeting running expenses of embassy — Whether subject to execution in receiving State

Sources of international law — Judicial decisions — Decision of Federal German Constitutional Court as evidence of customary international law — The law of Austria