Tokyo, Nov 21 (IANS/EFE): A 67-year-old Japanese woman is suspected of having poisoned her husband and possibly six other partners, from whom she inherited around $8.47 million, investigation sources said Friday.

Chisako Kakehi, dubbed the "Black Widow of Kyoto", received in addition to the inheritance from her last spouse, who died in December 2013, the assets of three other husbands after their deaths.

Her modus operandi was to use most of the usufruct to buy shares and make investments, after which she would approach other men in an attempt to secure new funds, the sources told the Kyodo news agency.

Despite the amounts inherited over the past years, Chisako has accumulated debts amounting to more than $84,863, they said.

Police arrested Chisako Wednesday after the autopsy of her last husband detected the presence of cyanide in his heart and stomach.

Chisako began to be investigated after it was discovered that she had received millions in insurance and also assets inherited from her partners over 20 years.

Although police have not confirmed it, Japanese media revealed that traces of poison were found in the blood of one of her partners, who died suddenly in 2012 while driving his motorcycle.

According to acquaintances, Chisako Kakehi, who worked in a bank until her recent retirement, had a total of 10 partners, between husbands and boyfriends, seven of whom have died.

Her first husband, to whom she was married for a long time, died at age 54 in 1994, while the second died of a heart attack in 2006 at 69 and the third in 2008 at 75.

The woman then had three boyfriends, one who died in 2009 and the other two in 2012 and 2013.

Tokyo Police said her last husband, Isao Kakehi, was poisoned with cyanide Dec 28, 2013, after less than two months of marriage.