The Philippine Supreme Court has refused to block the arrest of Senator Ronald dela Rosa, who is wanted by the International Criminal Court (ICC) for alleged crimes against humanity.

Senator dela Rosa is sought by the Hague-based court for his role as the chief architect of President Rodrigo Duterte’s controversial “war on drugs” campaign between 2016 and 2022. This protracted campaign resulted in thousands of alleged drug dealers being killed in police operations.

President Ferdinand Marcos Jr’s spokeswoman, Claire Castro, stated on Wednesday that the arrest warrant is considered valid against Senator dela Rosa. The senator, whose current whereabouts are undisclosed, had previously argued that foreign arrest warrants cannot be enforced in the Philippines without local court authorization.

The Supreme Court’s interim ruling on Wednesday removes a significant legal obstacle to the potential arrest of dela Rosa. This development comes amidst a dramatic sequence of events that began last week when authorities confirmed their intention to arrest the senator.

Dela Rosa had initially taken refuge at the Senate building for several days after emerging from six months of hiding. He reportedly fled the premises early Thursday following a shooting incident involving government agents and Senate security personnel, which prompted senators to seek shelter in their offices.

Dela Rosa’s legal counsel indicated that they intend to pursue all available legal avenues, including filing a motion for reconsideration. The lawyer emphasized that the court’s resolution is not a final judgment on the merits of enforcing ICC processes within Philippine territory.

Justice Secretary Fredderick Vida had previously stated last Friday that authorities would “definitely” seek to arrest dela Rosa and execute the ICC warrant. The Supreme Court, however, clarified that while the restraining order was denied, other aspects of the senator’s petition remain to be addressed.

Dela Rosa, during the height of the anti-drug campaign, served as the chief of the Philippine National Police. The ICC estimates that between 12,000 and 30,000 people were killed from 2016 to 2019, with police attributing many killings to vigilantes and drug-related turf wars.