CYCLISTS and walkers are constantly passing by, eight lanes of traffic roar above and trains zoom past every few minutes.

However for six months nobody noticed the remains of a forgotten man who had lived in a humpy under one of Melbourne's busiest roads.

A police officer looking for graffiti vandals found his skeletal remains near the rail tunnel under Dandenong Rd, Windsor, about 1.30am yesterday.

Police said the man, believed to be in his 40s, had lived under the bridge for about 18 months.

Welfare workers said the lonely death was an indictment of society.

"He just wasn't significant enough in people's lives," Salvation Army spokesman Major Brad Halse said.

"It's hopefully something of a lesson for us to take more notice."

Social worker Les Twentyman said it was almost as if the man hadn't existed.

"It shows how insignificant homeless people become," he said.

"Homeless people are also part of our society and this says something about all of us."

The man is believed to have died of natural causes, but police have not ruled out foul play.

Det Sen-Sgt Jeff Maher, of the homicide squad, said the area was a haunt for vandals and drug users.

"We believe we know who the person is but we need to follow this up to make sure the circumstances aren't suspicious," he said.

Commuters at Windsor station were shocked.

"It's just so sad that a vagrant could be lying there dead and no one noticed," said Gill Thomas, of Moorabbin.

"No one knew about it and no one cared.

"It makes you feel as though anyone could crawl under there and die. It could have been a murdered person and no one would know."

Anna Brown, of St Kilda East, said people no longer cared for others in the community.

"It's pretty sad," she said. "Society's become pretty alienated and everyone just does their own thing."

Ms Brown said she was concerned by reports of elderly people whose deaths had gone unnoticed for months at a time.

"There's a couple of elderly people in my block of flats and we keep an eye on them to make sure they're OK," she said.

"We were brought up to respect elderly people.

"But it's hard. Everyone just looks through homeless people."

Major Halse said some homeless people preferred to live outdoors and live rough.

"This will only change . . . when we think about the community more than ourselves. When we take notice and take care, look people in the eyes and say, G'day."

Melbourne Citymission CEO Anne Turley said there was a need for more housing for the homeless.

"There is a shortage in Melbourne. There are a lot of people disconnected from their support networks.

"It's a very sad statement on our community.

"The needs of people like this get overlooked in people's busy lives."