The International Criminal Court (ICC) has rejected the Philippine government's request to suspend its ongoing investigation into former president Rodrigo Duterte's war on drugs.

In a decision dated March 27, 2023, the ICC Appeals Chamber denied Manila's plea "in the absence of persuasive reasons in support of ordering suspensive effect."

This came after the government submitted two requests—a notice of appeal in February and an appeal brief in March—to suspend the probe after ICC authorized its prosecutor, Karim Khan, to investigate the Philippine situation "in relation to crimes committed" during the Duterte administration's fight against illegal drugs.

With the decision, Khan and his office may freely conduct their probe.

According to the appeals chamber, it rejected the government's appeal because at the onset, the Philippines "did not include any reasons and arguments" to support its request.

The body said it would "have been preferable for the Philippines to have included its supporting arguments for the Request in the Notice of Appeal" and not in the latter Appeal Brief.

On March 13, Manila objected to the ICC investigation by making three contentions. It said ICC did not have any legal foundation to do so; its mandate would have adverse implications to the suspects, witness and victims; and it would have "far-reaching and inimical consequences."

But in its decision, the appeals chamber argued that the Philippines failed "to explain how the alleged absence of jurisdictional or legal basis" would defeat the ICC's purpose as well as create an irreversible situation that could not be corrected.

Regarding the supposed adverse implication and far-reaching consequences, the appeals chamber argued that the country failed "to provide any explanation as to what those implications may be and how the broad scope of the Prosecutor’s investigation at this stage of the proceedings would lead to consequences that would be very difficult to correct and may be irreversible."

"Lastly, the Appeals Chamber notes that as far as national investigations are concerned, the Philippines is in a position to continue its investigations irrespective of the ongoing proceedings before the Court," it also said.

In September 2021, ICC launched a formal inquiry into the war on drugs. But it suspended its move two months after following Manila's pronouncement that it was re-examining the cases of drug operations that led to many deats.

In June 2022, the ICC prosecutor requested to reopen the inquiry. The ICC pre-trial chamber eventually allowed its resumptions because it was "not satisfied" with what the Philippines was doing.