A teenager allegedly involved in a group attack on an American surgeon and his son during the Australian Open has been slapped with new charges.

The boy, who cannot be named, is one of three 17-year-old boys charged with seriously assaulting surgeon Edmund Pribitkin and teenage Edik and robbing the pair in Melbourne's Queen Victoria Gardens on January 17.

Edmund Pribitkin in hospital after the alleged assault. Credit:AP

The accused teen returned to a children's court on Monday, where his lawyer revealed his client faced new charges over an alleged fight at the Melbourne Youth Justice Centre on February 2.

It's alleged the 17-year-old boy hit and kicked other inmates after being attacked in custody.