Four men have been arrested over the death of a man in the central Japan prefecture of Aichi after his body was discovered in August in a concrete-filled drum in Aomori Prefecture in the northeast, police said Thursday.

The Aichi police allege the suspects assaulted Takashi Hiratsuka, a resident of Komaki, Aichi, in early February 2015 by punching and kicking him in the chest and abdomen. They were arrested Wednesday on suspicion of causing bodily injury resulting in death.

Hiratsuka, who worked in interior finishing, and the others are thought to have known each other. Shigeru Katsuta, 51, a company executive from the local area, is among the suspects.

The oil drum containing the victim's body was found in an open space in Hirosaki, Aomori, according to the police. Officers discovered it after receiving a tip.