A 19-year-old Thai woman has died in a Tokyo hospital after being severely assaulted in a hotel room on Tuesday.
Japanese media reports said the prime suspect in the case, a Japanese man, jumped from the fifth floor room's window after the assault.
Foreign Ministry spokeswoman Busadee Santipitaks said on Thursday the Thai embassy in Tokyo had reported the Thai tourist was pronounced dead at a hospital in the Japanese capital. Police had yet to officially report on the cause of death.
The Department of Consular Affairs had informed the victim's mother, she said.
Japanese media reported that a naked woman was found unconscious, severely beaten about her face and body, in her room on the fifth floor of a love hotel near the Jr Uguisudani train station in Tokyo about 8.30pm on Tuesday.
A Japanese man in his 20s was also found unconscious, with a broken skull, on a footpath in the street outside the hotel.
Hotel staff said that a short time earlier they heard sounds of a loud dispute emanating from the couple's room, and the woman screamed.
The online newspaper Japan Today reported that the Japanese man was in the room when police arrived after being informed of the loud quarrel and scream.
He refused to open the room door, and instead jumped out of the fifth floor window.
The report said the woman died in hospital on Wednesday evening.
According to the English-language news website Tokyo Reporter, the unconscious man was lying directly below the room's open window.
He was taken to hospital, where he underwent surgery. Police planned to question him after he recovers sufficiently from his injuries. It was earlier reported he had died in the fall.