A lucrative racket in human misery has been uncovered by a Melbourne ghost-hunter who investigates reports of hauntings and possessions.

The psychic investigator, who charges no fee for his services, says crooks are cashing in on people's fear of the supernatural.

"One charlatan got away with $20,000," says Drew Sinton.

"I've heard of others charging exorbitant fees for mumbo jumbo they probably learned by watching The Exorcist. "

He says one Italian woman was terrified by what she regarded as an evil spirit, and discussed her fears with a pseudo-expert on the fringe of spiritualism.

She was told by the con-man that medicine and the church could not help her. The only way she could be freed was to pay him $20,000 and he would exorcise the demon.

"The poor woman fell for it," says Drew, who is campaigning to drive out all pseudo-exorcists.

"She and her husband mortgaged their house to raise the money, they paid the con-man, and he hasn't been seen since. I'm tracing him and so are spiritualist church members.

"We'll demand that he refunds the money."

Drew is a freelance writer who is working on a book about ghosts, hauntings and possessions. He says some frauds are preying on vulnerable people in Melbourne.

"I'm sure the same sort of thing happens elsewhere in Australia," he said.

"My advice is never pay money to people who claim to be able to drive out demons."

However, there are plenty of genuine people who can help, the psychic investigator says.

These can range from members of the medical profession to specialist priests who have studied paranormal phenomena.

"I don't claim to be able to do the job myself," Drew said. "You might call me an assessor, a go-between. I try to work out what the problem is and the best way of fixing it.

"I work with medical practitioners such as psychiatrists, with orthodox church people, with spiritualists and with people who have a genuine reputation for helping."

Drew says inexplicable phenomena abound everywhere. He has witnessed many happenings and has records of many more.

"In an Anglican church in Broadmeadows (Melbourne), the congregation watched a woman who was possessed. The presence of Jesus, through the church and the priest, made her unable to stand. She had to be propped up by wardens.

"In a very short time and with a minimum of drama the priest commanded the spirit to be gone.

"It emerged from the woman as a scream that made its way down the nave, above the congregation and into the street.

"Dogs barked as the scream went past them. It faded away down the street. The woman, who previously was on the verge of total mental and physical collapse, was restored to health on the spot."

Drew says police and community leaders are aware that some people can provide non-medical help to those who are apparently haunted or possessed.

"Some of these people are called rescue workers," he said.

"It's dangerous work - the demon might stay in the body of the priest or medium. That happened recently to a spiritualist, who subsequently had a total collapse."