In scathing remarks targeting the chief of the Philippines human rights watchdog, President Rodrigo Duterte attacked him asking if he was a paedophile for investigating cases of young teenagers' murders in the government's bloody war on drugs.

Speaking at press conference in Davao city on Saturday (16 September), Duterte renewed his criticism of the Commission on Human Rights (CHR) and its Chairman Chito Gascon.

Gascon is known for his outspoken views criticising the Duterte administration for its brutal and controversial anti-drug campaign that is reported to have killed thousands of Filipinos over the past 15 months.

"Why is this guy so pre...suffocated with the issue of young people, especially boys? Are you a paedophile?" Duterte asked, referring to Gascon.

"Why are you smitten with teenagers? Are you? I'm having my doubts. Are you gay or a pedophile?" he added, according to Reuters.

Duterte's comments came days after the Philippines congress allied with Duterte voted to slash the annual budget of the CHR to just $20.

Although the budget still needs the approval of the Senate, opponents of the measly allocation fear it is likely to get passed as Duterte has a majority in the two chambers.

The Filipino president also accused the CHR chief of being a spokesman for the opposition, while criticising Gascon for investigating a wave of police and vigilante killings since the war on drugs was launched.

"Why can't you move on to other issues that are besetting this country?" Duterte said. He referred to the plight of tens of thousands of civilians in the besieged Marawi city, where the Filipino troops are battling the Islamic State-linked insurgents.

One-third of those killed as part of the alleged war on drugs were thought to have died in raids and sting operations by police, who claimed to have acted in self-defence.

Duterte has long justified such killings as self-defence and has even ordered the police forces to kill "idiots" if they resist arrest, amid a string of troubling cases of extrajudicial killings.

CHR spokeswoman Jacqueline de Guia condemned the president's remarks, saying it diverted public attention from the critical human rights issues in the Philippines, Reuters reported.

"These are remarks that do not show respect for the dignity of others. The public must understand that the death of children concerns us all as they are especially vulnerable and need state protection," De Guia told the news agency.

The CHR has long been appealing for increasing its budget, saying it lacks the manpower and resources to fully probe the killings.

Even after the Philippine congress announced the budget slash to $20, Gascon is reported to have appealed to the Duterte government for more funding.

But Duterte is thought to have proposed using the $38m budget withdrawn from the CHR to fund body cameras for his police force if the legislators prefer not to restore funding for the organisation.

Duterte State of the Nation address
Philippine President Rodrigo Dutertes comments came days after the Philippines congress allied with Duterte voted to slash the annual budget of the CHR to just $20Noel Celis/AFP/file photo

The CHR is reported to have sought a 1.72bn pesos budget for 2018, but the government instead proposed only 678m pesos ($38m). The agency was allotted a budget of 749m pesos for the year 2017.