A 48-year-old man was arrested Thursday on suspicion of fatally stabbing a woman and seriously injuring her 4-year-old daughter in Osaka Prefecture, investigators said.

The man, believed to be a former partner of Megumi Futase, 35, allegedly stabbed her and her daughter Wakaha at a condominium in the city of Sakai on Wednesday night. Futase was pronounced dead after being rushed to a hospital.

The man later visited the home of a female acquaintance nearby and told her he "stabbed" the mother and daughter. He also left a knife at the acquaintance's home. The woman then went to the condominium and called an ambulance at around 10 p.m., according to investigators.

The suspect turned himself in to the police at around 4:30 a.m. Thursday, telling investigators, "We had a fight over Futase's dieting methods."

In May last year, Futase reported to the police she had been slapped by a man living with her, and that he had stepped on her shoulders. Police stopped handling the case around two months later after she told investigators she had separated from the man.