Prosecutors on Thursday charged a policeman with murdering his wife earlier this month at their home in Fukuoka Prefecture, where their two children were also found dead.
Mitsuru Nakata, a 38-year-old sergeant with the prefectural police, is accused of strangling his wife Yukiko, also 38, shortly after midnight on June 5, according to the indictment. The police are still investigating if he was involved in the children's deaths.
Investigative sources said Nakata continues to deny the allegation.
Nakata, who works for the prefectural police's communications dispatch division, was arrested on June 8 after the police recovered evidence from one of the wife's fingernails, suggesting she scratched him in a struggle, they said.
The sergeant has told investigators that he left for work early on June 6. He had been living in the house in with his wife and their son Ryosuke, 9, and daughter Miyu, 6.
The victims' bodies were found after Nakata's sister-in-law visited their home. The sister-in-law found the wife lying face up in the kitchen on the first floor, while the two children were found dead in their bedroom on the second floor.
Given that the house was filled with smoke, the police suspect Nakata attempted to burn it to destroy evidence.