The Immigration Bureau admitted Thursday that it mishandled the case of a 43-year-old Cameroonian detainee who fell ill and died after he was left without access to medical treatment at an immigration facility in Ushiku, Ibaraki Prefecture.

The man, whose name has been withheld, was found unconscious in his cell on the morning of March 30. He was taken to a hospital but died an hour later, according to an internal survey conducted by the bureau. The cause of death remains unclear.

Three days earlier, on March 27, the man complained that he was ill and went to see a doctor at the facility. A doctor who works there full-time was absent that day, so he was treated by the part-time physician.