The International Criminal Court (ICC) has rejected a bid by former president Rodrigo Duterte to challenge the tribunal’s jurisdiction over crimes linked to his administration’s bloody war on drugs, clearing the way for proceedings against him to move forward.

In a 32-page decision released late Thursday, Oct. 23, the ICC Pre-Trial Chamber I said the Philippines’ withdrawal from the Rome Statute in 2019 does not affect the Court’s jurisdiction over crimes allegedly committed while the country was still a member.

According to the judges, countries cannot “abuse” their right to withdraw from the Rome Statute “by shielding persons from justice in relation to alleged crimes that are already under consideration.”

Duterte’s legal team, led by lawyer Nicholas Kaufman, argued that since the Philippines left the ICC before a full investigation was opened, the Court had no authority to proceed. Prosecutors announced a preliminary examination into the Philippine situation in February 2018, while Duterte ordered the country’s withdrawal from the ICC the following month.

Judges, however, disagreed, ruling that the prosecutors’ 2018 preliminary examination was already substantial enough to place the alleged crimes “under consideration” before the withdrawal took effect in March 2019.

Under ICC rules, a member state’s withdrawal does not affect matters already under consideration by the Court.

The ICC investigation covers alleged crimes against humanity committed between November 1, 2011, when Duterte was still mayor of Davao City, and March 16, 2019, the date the Philippines’ withdrawal from the Rome Statute became effective.

The Court has been examining thousands of killings linked to Duterte’s anti-drug campaign, which claimed at least 6,000 lives according to police reports, and up to 30,000, according to human rights groups.

The 80-year-old Dutert was arrested and transferred to The Hague in March following an ICC warrant accusing him of orchestrating murder as part of a widespread and systematic attack against civilians. He has denied all charges.

Thursday’s ruling did not address a separate motion from Duterte’s lawyers seeking to halt proceedings because he is supposedly “not fit to stand trial.” The judges have ordered an independent panel of medical experts to assess his condition, with a report expected by the end of October.

A final decision on his fitness to face trial is expected in mid-November.

In the meantime, Duterte will remain in detention, with judges earlier ruling that he poses a flight risk.

Kaufman said the legal team anticipated this decision and will appeal it.

The Duterte administration had previously sought to suspend the ICC investigation, arguing that Philippine authorities were already addressing the same allegations. But in 2023, ICC appeals judges ruled that the probe could resume, reaffirming that the international court retains jurisdiction despite Manila’s withdrawal.

Early this month, the ICC denied Duterte's request for interim release, saying his continued detention remains necessary under the court’s founding statute. The Prosecution has said that Duterte's detention remained necessary due to his rejection of the court’s authority. They also warned that his release could jeopardize witnesses and obstruct ongoing investigations, and cited his past public remarks that might encourage violence.