An official who did not want to be named said on Thursday that an unidentified Nigerian man has died in a Japanese immigration detention centre.
His death brings to an end a hunger strike an activist group, RINK, said was intended to protest against his over three years detention.
According to sources, the man, in his 40s, died on Monday in the southern city of Nagasaki after he lost consciousness and was taken to hospital.
Foreigners being held in Japan have recently resorted to hunger strikes to protest their lengthy detention.
About 27 foreigners are said to be on hunger strike at a detention centre in Ushiku, northeast of Tokyo.
The Nigerian’s death was the 15th since 2006 as critics decry poor medical facilities and emergency response in the detention centres.
An official at the national immigration agency said authorities are providing medical care and trying to persuade those on hunger strike to eat
As recently as June 2018, Japan held about 1,500 detainees, nearly half of them for over six months.
Some 604 were asylum seekers whose applications were rejected, while the rest were held for various immigration infractions such as overstaying visas.