She will appear in court today to hear a medical opinion on the child's injuries.

The boy's parents told police the nanny had battered him. She remains in custody.

Baby MJ Artwyutthikulwong is fighting for his life in intensive care after sustaining serious internal injuries and broken bones.

Parents Suwit and Isaree rushed their son to Bumrungrad Hospital on March 16, one day after employing nanny Boonreung Katasarn.

The Bang Sue couple filed a police complaint against Boonreung four days later and she was charged with assault and causing serious injury, according to Tao Poon police officer Lt Colonel Col Su-ek Chinthanasab.

Boonreung denies the charges, saying the infant was hurt in a bath-time accident. The child slipped from her grasp and hit his head twice on the floor, she told reporters.

Isaree said neighbours overheard Boonreung in a heated phone call, and suspect she lashed out at the child.