Black widow arrested - A 67-year-old Japanese woman has been taken into custody by the police in Kyoto after the autopsy results of her late husband revealed the presence of high levels of toxic cyanide in his body.

Isao Kakehi, 75, is reportedly the seventh partner of the black widow arrested - Chisako Kakehi - to suddenly drop dead in the past two decades. Local sources say the black widow arrested had amassed up to 800 million yen ($6.8m) through the insurance payouts and other inheritances from her late partners. But Japan's Youmiuri newspaper said the black widow arrested had invested badly in futures markets and was in debt by the time she tied the knot with the late Mr. Kakehi.

According to Jiji Press, Mr. Kakehi's death in December 2013, after less than two months of being married to the black widow, came after the passing of her 75-year-old boyfriend in September that same year.

But the murder spree of the black widow arrested goes way back to the 90s. Reports indicate that her first husband, who was 54, died in 1994. Several years later, in 2006, her second husband died from a stroke at 69. Her third husband, who was 75, also died in 2008. In 2009, her boyfriend, who is reported to have been suffering from cancer added to the list of deaths around her. Again, in 2012, another boyfriend collapsed and died while riding a bicycle.

Although an unidentified investigator has revealed that the black widow arrested may have killed these seven men for their money, officials say it is too early to make conclusions.

"We can't say how many now...given their advanced age, we have to proceed carefully to judge whether their deaths were actually the result of foul play or not," an investigator said to AFP.

The black widow arrested is reported to have met most of her partners through dating and marriage agencies. Local sources say she had been actively seeking for a new partner prior to her arrest. She allegedly seeks out partners who meet a particular profile; they had to be aged, living alone, rich and preferably ill.

The black widow arrested has denied killing her partners. "If people suspect murder, I'd find it easier to bite off my tongue and die," she said to the press earlier in the year.

The former banker told the police that she is inexperienced in the use of poisons. "I don't even know how to kill someone. And I don't know where the cyanide came from. I wish someone would tell me," she said.

But on Thursday, investigators found cyanide hidden in a trash container in the home of the black widow arrested. Reports indicate that a prosecutor would decide whether to press charges after questioning the black widow arrested.