A 67-year-old woman from Kyoto Prefecture was arrested on Wednesday on suspicion of killing her husband with cyanide, as it emerged that a string of former partners had died shortly after becoming romantically involved with her.
Chisako Kakehi denied murdering Isao, 75, who died at the couple's home in the city of Muko, Kyoto Prefecture, on Dec. 28 — just a month after the two were married. An autopsy revealed quantities of cyanide in his blood far exceeding a lethal dose.
The couple had met via a matchmaking service and Isao had been covered by life insurance at the time of his death, the sources said.
Cyanide was also found in the blood of a 71-year-old man from Osaka Prefecture, who died on March 9, 2012, after falling off a minibike. Although at the time he was believed to have died from heart disease, the discovery of cyanide prompted police to launch an investigation into his death.
Kakehi has also denied being involved in the 71-year-old's death, and told reporters she had "absolutely no idea" about cyanide.
She did say, however, that she had married four times, and admitted that several of her former partners in Osaka and Hyogo prefectures had died within a few years of meeting her.
Despite her arrest, police said there is currently no evidence that Kakehi acquired cyanide, and little indication of how Isao imbibed the substance. No suicide note, food or drink was found near his body.
Kakehi is being held by police pending further investigation, and has been placed on suicide watch.