A mother has been arrested on suspicion of murdering her 12-year-old daughter, whose dismembered body was found in a Mong Kok flat on Sunday night. Police arrived at the subdivided flat on the third floor of Man Fuk Building on Canton Road just after 9pm after a neighbour complained that the suspect – a 37-year-old masseur surnamed Cao – had refused to return a mobile phone. The suspect was standing outside the flat when police arrived. Since she refused to cooperate, officers had to break down the door to enter the 60 sq ft flat and found a dismembered body in the bathroom. The Post understands that the girl was born on the mainland and was the daughter of Cao and her former mainlander husband. Cao had later married a Hong Kong man, and in 2013, moved to the city with her daughter. Police are investigating whether the woman divorced her Hong Kong husband. The girl was a Hong Kong identity card holder who had been studying in the city. Initial investigation showed all the dismembered body parts were found in the bathroom of the flat, according to a police source. He said traces of human tissue were also found in the toilet bowl. Son who chopped up parents and kept heads in the fridge jailed for life in Hong Kong “We believe the girl was dismembered in the bathroom, which caused the drain to clog. Water mixed with blood flooded the [piping system],” the source said. He said a meat cleaver, believed to be used on the body, was found in the flat. “No illegal drug was found, but an instrument used to take the drug Ice was discovered,” he added. Mong Kok assistant district commander Chung Chi-ming said: “Her head, organs and body had been mutilated. The bathroom had flooded which was affecting neighbouring flats.” Police said there was no record of Cao’s mental history or domestic violence. She was a long-term resident in the city and police would attempt to locate the girl’s father. When asked if Cao appeared delirious or had resisted when she was arrested, Chung only said she was not able to cooperate with officers at the time: “We have to wait until her situation gets better to investigate.” She has been detained for questioning. A neighbour surnamed Tsui, who lives opposite the crime scene, said on Monday that she heard chopping noises that lasted about half an hour coming from the flat at around 3pm on Sunday. She also smelled strong antiseptic. Tsui claimed she often said hello to Cao but had never seen the girl before. Chung said they were looking for related tools the woman may have used. Forensic pathologists were at the scene on Monday morning. The girl was a Primary Six pupil at the nearby Tong Mei Road Government Primary School in Mong Kok. School authorities said they were saddened by her death, describing her as a pupil with “good conduct” who had a “good relationship with teachers and schoolmates”. The school has a contingency plan in place to counsel pupils who may have known the girl and are emotionally affected by the incident.