Under customary international law, state representatives benefit from immunity while they are abroad due to the official duties they fulfil. A distinction is generally made here between personal immunity (ratione personae) and functional immunity (ratione materiae).
Heads of state, heads of government and ministers for foreign affairs benefit from personal immunity throughout their time in office. They thus enjoy absolute immunity from all prosecution abroad for any acts performed in a private or official capacity, either before or during their mandate.
Other members of the government have recourse to functional immunity, which protects them from all prosecution abroad for any official acts performed while in office. However, they do not enjoy immunity for acts performed in a private capacity.
In certain cases, state representatives do not benefit from immunity. For example:
- When a state expressly revokes the immunity of a representative, that representative may no longer invoke it.
- The immunity of a head of state, head of government or minister for foreign affairs for acts performed in a private capacity ends when they are no longer in office. They can then only invoke immunity for actions performed in an official capacity in the course of their duties.
- When an international agreement – applicable to the case in question – provides for a waiver of the immunity of state representatives (for example the Convention on the Prevention and Punishment of the Crime of Genocide of 9 December 1948).
- Certain international courts, such as the International Criminal Court, the International Criminal Tribunal for the former Yugoslavia, the International Criminal Tribunal for Rwanda and the Special Tribunal for Lebanon, are able to judge the criminal responsibility of a state representative without regard to any jurisdictional immunity her or she might enjoy under domestic or international law.
Discussions are taking place at the international level regarding the scope of state representatives’ immunity, particularly in relation to the most serious crimes (crime of genocide, crimes against humanity, war crimes, crime of apartheid, torture and enforced disappearance). These discussions aim to determine whether national jurisdictions can refuse immunity in some cases. Swiss courts have not yet recognised any exceptions to ratione personae jurisdictional immunity, even for crimes under international law. However, the Federal Criminal Court has ruled that one cannot prevail itself of the defence of ratione materiae immunity in a criminal procedure for crimes under international law (Decision of 25 July 2012 of the Federal Criminal Court, BB 2011 140, c. 5).