First came a high fever. Then her face and limbs turned numb. Soon, she could keep down little more than water, sugar and bites of bread as she wasted away in her cell in a Japanese detention center.

By early March, Ratnayake Liyanage Wishma Sandamali — a migrant from Sri Lanka who was being held for overstaying her visa — could barely make a fist and was having trouble speaking, according to government records detailing her care.

Yet week after week, as she begged to be released to a hospital for treatment, her jailers refused. She and her supporters believed they knew why: The authorities, even as her health deteriorated, suspected that she was faking her illness to avoid deportation.