A yet-to-identified Nigerian, has died in a Japanese immigration detention centre, an official said on Thursday.
An activist group said the African died of hunger strike, which was intended to protest him being held for more that three years.
According to Reuters, his death was the 15th since 2006 at the centre that has been criticized for poor medical standards, including monitoring of detainees and how guards responds to medical emergency.
The man, said to be in his 40s, died on Monday in the southern city of Nagasaki, after he lost consciousness and was taken to hospital, a detention centre official was said to have revealed.
However, he did not mention the cause of death.
RINK, a group supporting detainees at the centre, told Reuters the Nigerian had been on hunger strike to protest his long detention.
Some of them are said to have gone without food for 47 days, Kimiko Tanaka, a spokesperson for the group disclosed.
She said a 23-year-old Iranian man, who sought asylum more than two years ago has lost weight and is using a wheelchair.