An 11 year old boy with autism is recovering in hospital in Melbourne after spending four days lost in rural Victorian bushland after wandering away from his family's campsite.

Luke Shambrook went missing on 3 April sparking a massive search involving police, helicopters and hundreds of volunteers, local media reported.

He was spotted by a police helicopter on 7 April in bushland just a few kilometres from where he went missing suffering from dehydration, hypothermia and fatigue, police said.

"When I first heard it I wondered whether or not they'd spotted a volunteer searching that was my... I didn't want to get my hopes up too much, but absolute relief I have to say after 4 days and 4 nights, absolute relief. The joy on the people's faces in our command post and all of those assisting was just fantastic," Acting Commander Rick Nugent from Victoria Police said.

The search included tourists on holiday in the area for the Easter weekend, reports said.

"Probably one of the most rewarding of my career. The emotion I was feeling was amazing. He was mumbling to us, we gave him some food and water. I held his hand and talked to him. I had information from his medical team and his parents and family, his likes and dislikes so I was trying to talk to him about those things, I mean a small boy and talking about Easter and helicopters and all the fun things yeah," said Brett Sergeant, a volunteer member of the State Emergency Service, who was one of the first to reach the boy.

Doctors at Melbourne's Royal Children's Hospital said Luke is stable and is in a better condition than they would expect considering his ordeal, reports said.