TOKYO, Nov. 21 (UPI) -- Japanese authorities are investigating a 67-year-old woman the media has dubbed a "black widow," accused of killing her fourth husband amid speculation that previous partners may have met a similar fate.
Chisako Kakehi was arrested Wednesday on suspicion of poisoning her 75-year-old husband with cyanide on Dec. 28, 2013, two months after their wedding.
Kakehi maintains her innocence. "I didn't kill him. I don't know how to kill," she told police, according to CNN affiliate TV Asahi.
Her previous three husbands and two men she dated all died within several years of meeting her.
According to Japanese media, Kakehi received $6.8 million in insurance money over the past 20 years from the policies of at least five previous partners.
Police are investigating the death of at least one of the men with whom she had a close relationship. The 71-year-old died of apparent heart failure in March 2012 but upon re-examination of a blood sample taken at the time of his death, police detected a trace amount of cyanide.
It is unclear to what extent investigators will be able to re-examine the cause of death of previous partners because autopsies in Japan are rare.
Two other "black widows" in Japan, Kanae Kijima and Miyuki Ueta, are serving death sentences for killing multiple men.
