Meet Japan's 'Black Widow': the accused killer the world can't stop talking about.

A 70-year-old woman who has been dubbed Japan’s ‘Black Widow’, accused of the fatal cyanide poisonings of her husband and other men, has sensationally admitted to killing her late husband in her Kyoto trial.

Chisako Kakehi is on trial at the Kyoto District Court for the alleged murders of her husband, two boyfriends and the attempted murder of another boyfriend. As she took the stand on Monday, Ms Kakehi –  who has been on trial since June 26 – said she killed 75-year-old Isao Kakehi in December 2013 because she “wasn’t given any money” after she married him. Ms Kakehi and her husband had only been married a month when he collapsed in their home.

“I killed my husband,” Ms Kakehi said from the witness stand on Monday, The Japan Times report. “I have no intention of hiding the guilt. I will laugh it off and die if I am sentenced to death tomorrow.”

However, just days later, Ms Kakehi withdrew her statements and denied the killings, according to various news reports.

“I don’t remember [what I said],” she testified, according to the Mainichi newspaper.

Last year, medical examinations found that Ms Kakehi had early-stage dementia but was fit to stand trial, The Guardian reports.

It is believed Ms Kakehi had relationships with many men, often elderly, after meeting them through dating agencies after filtering out potential partners to find ones who were both wealthy and childless. Prosecutors are arguing the men were killed after Ms Kakehi was made the sole beneficiary of their life insurance policies.

The two other men Ms Kakehi is accused of killing - two of her late boyfriends  - were aged between 70 and 80. She is also standing trial for the attempted murder and robbery of another boyfriend who later died of cancer. All of the allegations occurred between 2007 and 2013.

Three of Ms Kakehi's other husbands also died in the time she was married to them, however she has not been charged with regards to their deaths.

Japan’s criminal justice system has attracted a lot of criticism in the wake of the trial, with many asking why Ms Kakehi was only arrested after the death of her fourth husband, with the deaths of her other partners not investigated.

Much of the evidence prosecutors are bringing to the trial is circumstantial, with more than 50 people expected to testify.

The trial is expected to continue until November.