On paper, the small rooms inside the flats in Din Daeng, a district in Bangkok, were packed with foreign children. A total of 64 foreign children had been registered as occupants in one flat alone – an implausible listing that authorities say has exposed a wider fraud in Thailand’s house-registration system. The children were not found living there. Their names, investigators say, have been fraudulently entered into official records, potentially opening the way to pink ID cards, access to public...