The family of an 11-year-old leukemia patient whose mother unexpectedly took her from a Phoenix hospital last month has a history of removing the child from medical facilities against the advice of doctors, police said Wednesday as the parents claimed the girl was being treated in Mexico.

The child, Emily, had been receiving chemotherapy at Phoenix Children's Hospital for about a month before her mother removed her on Nov. 28 while she was still being treated. An infection forced physicians to amputate her right arm and insert a catheter through her chest to deliver medications.

The child's mother removed an IV tube from the device and took her from the hospital, concerning doctors that she could succumb to a deadly infection, said police Sgt. Steve Martos.