Malacanang shrugged off on Tuesday the accusation of Communist Party of the Philippines founder Jose Maria Sison that President Rodrigo Duterte is the top drug addict.

Sison, in a statement, has said the president is an "addict user of the opioid Fentanyl" and "is most fitting target of the police units that he has turned into death squads and corrupted with money and promotions."

Duterte earlier admitted he used to take Fentanyl due to his ailment.

Presidential Communications Operations Office Assistant Secretary Kris Ablan said Sison has the right to freedom of expression.

"Regardless if Mr. Sison is outside of the Philippines, he remains to be a Filipino citizen. He has a Constitutional right to freedom of expression. If he wants to call the President that, that’s within his Constitutional right," he said in a press briefing.

Duterte and Sison have been engaged in word war due to the CCP's order to attack government troopers despite the peace talks.

The president decided to abandon the formal talks with the Communists following a series of attacks by the New People’s Army on police and the military. Celerina Monte/DMS