Police said Saturday they have arrested the son of a senior Hokkaido Prefectural Police official, along with four others, on suspicion of use and possession of stimulant drugs.

According to an investigation, Atsunori Maira, 28 and unemployed, the son of Akihiro Maira, head of the Kushiro district police headquarters, is suspected of using stimulant drugs he purchased from Masato Takiguchi, 29, also one of the five arrested, in Sapporo and its suburbs this month, they said.

Following his son's arrest, Maira has reportedly indicated to those close to him that he plans to resign, police sources said.

Police said they discovered the son had been using stimulants when they conducted a urinalysis after asking him to voluntarily come to the Kita Police Station in Sapporo for questioning Friday morning. The son has reportedly owned up to the allegations.

Maira joined the Hokkaido force in 1962 and has been head of the Kushiro district headquarters since February.

Ryuichi Kobayashi, counselor at the Kushiro district headquarters, said, "I have not heard of a formal resignation and I think he will conduct his official duties for the time being."