The 1999 Ang Mo Kio torture case refers to the torture and imprisonment of a 14-year-old girl which occurred between 15 December 1999 and 2 January 2000 in Ang Mo Kio, Singapore. The girl was tortured and abused in a Housing and Development Board flat in Ang Mo Kio in one of the most horrific cases in Singapore's history. The perpetrators of the case were three sisters Ong Li Xia, Ong Lay Hua and Ong Lay Hiong, and their boyfriends, Neo Soo Kai, Melvin Yeo Yew Beng, and Yeo Kim Han.[1][2]