Two of the four women arrested late last month on suspicion of murdering the husband of one of them have indicated that they also had a hand in the death of another one of their spouses, sources close to the case said Thursday.
According to the sources, nurse Kazuko Ikegami, 41, and medical test coordinator Miyuki Tsutsumi, 42, have told investigators that they injected air into the blood vessels of Ikegami's husband four years ago to make it appear that he died of heart failure.
The pair, along with former nurses Junko Yoshida, 42, and Hitomi Ishii, 43, were arrested in April for allegedly killing Ishii's husband by making it appear as though he died of acute alcohol intoxication.
The sources said that Ikegami and Tsutsumi are telling investigators that the actions taken against the former's husband, then 39, were under the instructions of Yoshida, who is believed by police to be the ringleader.
Police have already sent records and other data pertaining to the man's death to Kyushu University for analysis, the sources added.
According to investigations, Ikegami took her husband, whom she said she found in a comatose state in their home in Kurume, Fukuoka Prefecture, on the morning of Jan. 24, 1998, to a hospital, where he was pronounced dead about an hour later.
An acquaintance who had been drinking with the man into the late hours the previous night said there appeared to be nothing wrong with him, and Ikegami said that she went to wake her husband but found him comatose.
At the time, police determined the death to be caused by disease and did not perform an autopsy.
Ishii has told police that she has heard that Ikegami's husband was killed, while Tsutsumi has told acquaintances that there are "strange things" regarding the death, the sources said.