France on Wednesday became embroiled in a dispute with Philippine President Rodrigo Duterte over his deadly war on drugs as it stressed the importance of human rights and the rule of law.

The French embassy released a statement emphasising respect for human rights as it rejected comments by Duterte that people in France were presumed guilty until proven innocent.

"We have to point out that, as in the Philippines, the presumption of innocence until proven guilty is at the core of the French judicial system, based on the principles enshrined in the French Declaration of Human and Civic Rights of August 26, 1789," the statement said.

"France strongly believes in the importance of the rule of law, due process and respect for human rights in all countries, including the Philippines."

In a press conference on Monday, Duterte had reacted angrily to comments by the United Nations' special rapporteur on extrajudicial killings, Agnes Callamard, about the alleged murder by police of a 17-year-old boy as part of the drug war.

On her Twitter account, Callamard condemned the killing as "murder" and called for an investigation, saying the boy's death should be the last.

Duterte, who frequently uses coarse language particularly against critics of his drug war, lashed out at her personally.

"Daughter of a whore, tell her! Don't she dare scare me, daughter of a whore. She's an idiot! Where is that crazy person from?"

Upon learning she was French, Duterte said people in France were presumed guilty unless proven innocent. "Even in her own place, that happens. She's an idiot," he said.

"In their place, they can detain a person almost indefinitely under the French law. And the French law says you are guilty and you have to prove your innocence. That's how it works."

Duterte, 72, easily won presidential elections last year after promising to wipe out drugs in the country by waging an unprecedented crackdown in which tens of thousands of people would die.

Since he came to office 14 months ago, police have reported killing about 3,500 people in anti-drug operations.

More than 2,000 other people have been killed in drug-related crimes and thousands more murdered in unexplained circumstances, according to police data.

The United Nations, the United States and the European Union have condemned alleged rights abuses in Duterte's drug war, while rights groups have warned he may be orchestrating a crime against humanity.

Duterte said last year he would be "happy to slaughter" three million addicts to fix the drug problem.

After France released its statement on Wednesday, Duterte made an evening speech in Manila in which he accused French and other European governments of not understanding the Philippine justice system.

"Our revised penal code is retribution. It is an eye for an eye, a tooth for a tooth. That is the basic law of the jungle. If you violate and kill, you pay with your life," Duterte said.

Meanwhile, the deputy head of mission at the French embassy, Laurent Legodec, reinforced the message of the statement and called for all deaths in the drug war to be investigated.

"Of course we are concerned by what's going on," Legodec told AFP when asked about the death of the 17-year-old.

"The best I can say is that every loss of life, for whatever reason, is always a tragedy."

Source: AFP