His agent, Aidan Rodley, visited him today and said it was clear that he was in a "pretty serious state".
Rodley said that Walker's partner, Candace Smith, said he was making progress, with his condition continuing to stabilise.
Walker was unresponsive during Rodley's visit, but family members have reported him acknowledging their presence as he drifted in and out of consciousness during the past few days.
Recovery looked likely to be a long process, Rodley said.
Walker, 24, fell down a bluff in north Taranaki on Monday while carrying a slaughtered pig on his back.
The hospital said his condition tonight was stable.