PHOENIX (AP) — Authorities in Arizona say a girl with leukemia and a heart catheter could die if she isn't brought back to a Phoenix hospital after her parents inexplicably removed her last week.

Phoenix police are asking anyone with information to come forward. They say U.S. Border Patrol stopped the girl's father, Luis Bracamontes, as he crossed into Arizona over the weekend.

The man provided no clues and denied being involved in removing her from the hospital. Police are now seeking her mother, Norma Bracamontes.

The 11-year-old girl had been receiving chemotherapy at Phoenix Children's Hospital. Police say an infection forced doctors to amputate her arm and insert a heart catheter. The device was set to be taken out before her mother walked her out of the hospital Wednesday night.