MANILA - Police abuses may become normal in the Philippines as violence tends to be "legitimized" in countries that implement intensified crackdowns against illegal drugs, an analyst warned Saturday.

"The war on drugs legitimized and normalized police violence, evidence planting and bribery... when it was implemented in Thailand in 2003," Pascal Tanguay of the Law Enforcement and HIV Network said in a drug policy forum at the University of the Philippines in Diliman.

He said the same trend may happen in the Philippines as President Rodrigo Duterte "copy-pasted" his policy from Thailand.

"The Philippine war on drugs was taken from Thailand's playbook... Duterte just copy-pasted from Thakshin (Shinawatra)," he said in reference to the former Thai Prime Minister.

Filipino police officials have been criticized by the international community for at least 1,800 drug-related deaths and about 5,700 unsolved homicide cases since Duterte declared his crusade against drug users and peddlers in mid-2016.

Among these cases are the killing of former Albuera, Leyte Mayor Rolando Espinosa in his jail cell in November 2016, and the kidnapping and slay of a Korean businessman in January inside police headquarters Camp Crame. Duterte defended uniformed officials tagged in these controversies.

Tanguay said the same "promotion of violence and encouraged vigilantism" was observed in Thailand's drug war.

Of the 146,170 drug dependents who were arrested in Thailand between 2003 and 2008, 48 percent said police asked them for bribes, Tanguay said.

"(But) no one was held accountable in Thailand for the abuse of power during the war on drugs," he added.

Instead of mimicking a "failed" policy, Duterte should employ an "evidence-based" drug policy that would demonstrate to the international community how the drug problem can be effectively handled, Tanguay said.

"Duterte should take advantage of the 1 million drug users who surrendered to the government... There's an opportunity for the Philippines to show leadership on how the drug war should be handled," he said.