President Rodrigo Duterte said on Monday the shame campaign of slain Tanauan City Mayor Antonio Halili was just his front on his alleged involvement on illegal drugs.

In a speech in Maasin City, Southern Leyte, Duterte mentioned Halili's death and wondered who could have killed him.

"Earlier Mayor Antonio Halili in Batangas, there's a pretension of serious problem on illegal drugs. There's a pretension of parading the addicts. It's him. He was killed earlier," he said in local dialect.

"I don't know who killed him. I said don't get involved in illegal drugs," Duterte added.

Duterte said Halili was a drug suspect.

He said he could know if a mayor is allegedly involved in illegal drugs if he is wearing huge pieces of jewelry, such as necklace and bracelet.

Without directly mentioning Halili, he said there was a mayor who has a gold necklace with a diamond crucifix as pendant.

"That's obscene. You have a crucifix with a diamond?," he said.

Halili was shot dead by an unidentified sniper during Monday's flag-raising ceremony in front of Tanauan City Hall.

The slain mayor was included in the government's narco-list and in November 2017, the National Police Commission stripped him power over the police forces in his city. Celerina Monte/DMS