Nicanor Faeldon, chief of the Bureau of Corrections, said on Friday he had not been in touch with his son for six months and was not aware if he was involved with drugs.

"What I can assure everybody is that if my son is involved in any way, even if he is just a user, I will resign immediately and hunt him down," he said in a television interview.

"I will punish him. I will kill that idiot if he's involved."

Faeldon's son, Nicanor Junior, was arrested with three other people in a house in Naga City, 260 kilometres southeast of Manila, in a pre-dawn raid.

The raid was based on a search warrant issued by a local court against a 47-year-old businessman, who turned out to be the father of Nicanor Junior's common-law wife, Faeldon said.

Police seized seven sachets of suspected methampetamine hydrocholoride, locally called shabu, the most common illegal drug in the Philippines, during the raid.

Faeldon vowed not to interfere in the investigation but called on police to immediately determine if his son was involved in illegal drugs.

The former navy captain is a staunch supporter of President Rodrigo Duterte's aggressive crackdown on illegal drugs, which has seen nearly 5000 people killed in police operations since 2016.

Australian Associated Press