People wanting to help search for a missing boy in dense Victorian bushland have been told by police they are not needed.

A group of about 50 gathered at the Warburton police station east of Melbourne on Wednesday morning, wanting to volunteer.

But Victoria Police told them to go home and help instead by spreading word on social media.

William Wall, 14, left his Launching Place home before 7am on Tuesday to go for his daily walk in the Yarra Ranges.

The teenager told his family he would be gone for 15 minutes but didn’t return.

Police are worried about William, who has autism. Photo: Supplied/Victoria Police

William, who has high-functioning autism and is verbal, left home without his mobile phone.

The local weather deteriorated on Wednesday, with rain falling.

Inspector Jason Goddard said search organisers were trying to work out how to factor in the state’s coronavirus restrictions.

“We live in different times. We have to be very conscious of the COVID overlay with all this planning,” he told 3AW radio.

Georgia Strahan, a local resident who knew the area well, said she would be going out looking for William anyway.

“That’s what I would want people to do if that was my kid out there and he’d been out in the pouring rain and there’s trees falling and it’s dangerous and he had no food or water,” Ms Strahan told the ABC.

“I would want volunteers to be able to help. I think we should be.”

She said she would be willing to risk receiving a fine.

“I think it’s worth it,” she said.

Police are urging locals to check their homes and outbuildings.

The air and ground search involves police, including some on horseback, as well as the State Emergency Service and Bush Search and Rescue.

William’s father was emotional on Wednesday as he thanked the search effort.

“We’ve been out all night. I just want everyone to be safe,” Shane Wall said.

“I would never want to be in this situation but, man, the people around here are fantastic,” he added.

“I’ve been in the Valley for a long time but this has just blown me away, the support from local people, the Facebook community, the noticeboards and all that. Really top notch.”

Mr Wall appealed for anyone who thought they might have seen his son to immediately call triple-0.

He described William as “decent-size, fit, athletic kid” who preferred healthy protein bars and fruit to junk food and didn’t usually show any outward signs of autism.

Anyone who saw him should approach William in a calm, reassuring manner.

“Maybe just say his mum wants to talk to him, better than coming to me,” Mr Wall said.

“Just come home. We want you home.”

“The police, the SES are doing a top job, and people are getting out there and heaps of his mates and his brother’s mates are just all over the place.”

Searchers have been concentrating on the Warburton Rail Trail, which runs about 40km from Lilydale to Warburton and covers difficult terrain, and the O’Shannassy Aqueduct Trail above Warburton.

William is described as 177cm tall, with a lean build, mousy brown hair and a lazy right eye.

His family said he was wearing a dark hooded jumper, dark-coloured track pants, black runners and had a CamelBak hydration backpack.

William’s disappearance comes three months after another teenage boy with non-verbal autism was rescued after two nights in freezing bushland near Mt Disappointment.

William Callaghan, 14, was found by local bushman Ben Gibbs. He was suffering from exposure and a few injuries but otherwise well.

-with agencies