A Japanese woman convicted of murdering three former lovers faces execution after the country's Supreme Court rejected her final appeal.

Kanae Kijima, 42, was dubbed a "black widow" after three wealthy men she met online all died within eight months from carbon monoxide poisoning.

She was handed the death sentence in 2012 following the 2009 murders, but has spent years claiming her innocence.

Her defence team said the men – aged 41, 53 and 80 – all took their own lives, but the prosecution argued she killed the men to avoid repaying the vast sums of money she took from them.

The court sided with the prosecution and threw out her case for the final time on Friday (14 April).

Prior to the hearing, Kijima – who writes a blog from her detention centre – said in a post: "I hope to see you again somewhere someday."

Her case has garnered huge interest within Japan with thousands queuing up to attend hearings and with news flashes interrupting regular television broadcasts to deliver the verdict.

Kijima's first victim, 53-year-old Takao Terada was found dead in Tokyo in January 2009.

Kenzo Ando, 80, was then found dead in his home in the prefecture of Chiba the following May.

Yoshiyuki Oide, 41, was then found dead in a rented car three months later.

All three had died from briquette fumes.

In a similar but unrelated "black widow" case, 70-year-old Chisako Kakehi faces trial this June for the alleged murder of several men, who were formerly boyfriends and husbands.

The term "black widow" comes from female spiders who kill their male counterparts after mating.