A threatening letter has been sent to an immigration facility in central Japan over the death of a Sri Lankan woman while being held there, investigative sources said Monday.Police received a complaint from the Nagoya Regional Immigration Services Bureau in Aichi Prefecture on May 14 and have launched an investigation over the anonymous letter, which protested the 33-year-old woman's death and threatened to harm the facility's head, they said.Ratnayake Liyanage Wishma Sandamali, who came to Japan in 2017 on a student visa, was taken to the facility in Nagoya in August 2020 after it was foun…READ FULL ARTICLE