The recent rapid arrest and extradition of Philippine ex-leader Rodrigo Duterte to the International Criminal Court (ICC) in The Hague stunned the world. This was not so much because of the severity of the charges of crimes against humanity — which of course are extremely serious — but due to doubts concerning the legality of his arrest and extradition, which have sparked concerns over the rule of law and human rights issues in the Philippines.

The background to this debate is simple. Duterte is a former president of the Philippines, which formally withdrew from the ICC effective 2019. The ICC accused the ex-president of various crimes relating to his administration’s war against drugs in the years of his administration before 2019.

While the Rome Statute of the International Criminal Court, which governs the jurisdiction of the ICC, states that the latter has power over criminal acts committed while state membership still existed, the power of execution of that jurisdiction after the cessation of membership is very much in question.

There are several points of concern here. First, the ICC does not have a police force so obviously it has to rely on member states’ cooperation in arresting suspects after an arrest warrant has been issued where issues of due process and respect for human rights are met, not to mention state immunity.

Nonmember states have no legal obligation to execute such a warrant, let alone in the absence of due process and contrary to human rights. So the question is: Was Duterte arrested and extradited by the Philippines legally?

The plot thickened after the revelation of a letter formally issued by the current president of the Philippines Bongbong Marcos to his vice-president, Sara Duterte (a daughter of Rodrigo Duterte), barely three months before the arrest and extradition of Duterte Senior, in which he steadfastly asserted that his government “will not assist the ICC, in any way, shape and form”.

On the other hand, in an official statement issued by the ICC, it is stated that Duterte Senior was “surrendered” by the Philippine government. So who arrested and extradited Duterte Senior and on what authority?

Article 9 of the International Covenant of Civil and Political Rights (ICCPR) which applies to the Philippines states all individuals must have the right to be free from arbitrary arrest and detention, and any arrest must be lawful and based on clear legal grounds.

In a country where rule of law exists, this means any arrest and detention must be subject to the oversight of a court of lawful jurisdiction. Since Duterte Senior was arrested in the Philippines, that means the courts in the Philippines.

To this end, was Duterte Senior afforded an opportunity to appeal to a court of law in the Philippines to test the legality of his arrest under Article 2 (3) of the ICCPR, which gives him such right?

The elder Duterte’s extradition is also not without problems. The Model Law on Extradition issued by the United Nations suggests any extradition of a suspect to another country must meet the requirements of due process which encompasses a process by which the suspect has an opportunity to have the case against him tested in a court of law. That, apparently, never happened.

There are no less than two other issues of concern: First, does the ICC have proper jurisdiction to prosecute Duterte at all? The Rome Statute states clearly that the jurisdiction of the ICC exists only as a court of last resort.

This means that any crime must first be properly investigated by the member state, and jurisdiction for the ICC to indict arises only when the member state refuses or is unable to prosecute. Has this process started at all? And second is the issue of sovereign immunity.

The act complained of here was an act of a government; and its head of state usually has sovereign immunity under international and local law. Has the right been asserted by either Duterte Senior or the current administration in the Philippines, and has this issue been fully investigated?

The arrest and extradition of a former head of state is no small issue. Let’s not forget, Israel’s Prime Minister Benjamin Netanyahu is also subject to a warrant issued by the ICC for crimes against humanity. The world is looking on. At the very least, the world deserves a full and clear explanation from both the ICC and the Philippine government as to the legality of the arrest and extradition of Duterte.

The author is a former chairman of the Hong Kong Bar Association, a member of the Executive Council, and convener of the Path of Democracy.

The views do not necessarily reflect those of China Daily.