Chanting to cure snakebites, claiming to be a reincarnated spouse to obtain sex, and charging for miracles could soon be banned by an Indian state seeking to stop charlatans preying on the vulnerable.

Many superstitions are widely held in India but a campaign group is lobbying hard for a new law in the western state of Maharashtra to outlaw several exploitative activities, with penalties of fines or up to seven years in jail.

But the push to pass the Maharashtra Prevention and Eradication of Human Sacrifice and Other Inhuman, Evil Practices and Black Magic bill has not received unanimous support.

Some Hindu nationalists fear the legislation seeks to move beyond the excesses named in its title and might be used to curb cherished religious freedoms.

One right-wing association, the Hindu Janajagruti Samiti, called it "a draconian law targeting faith", denounced its proponents as "atheists" and called for supporters to lobby assembly members to oppose it and demand amendments.

The founder and executive president of the Maharashtra Blind Faith Eradication Committee, which has been calling for a law for the last two decades, is undeterred and hopes other states will follow suit.

"Superstitions are rampant all over India but at the moment there is no law which stops this type of activity," Narendra Dabholkar told AFP.

"There are laws against witchcraft but they're limited to a particular type of witchcraft. This is much wider and more encompassing."

The draft law, supported by Maharashtra's ruling Congress-National Congress Party coalition, aims to target "quacks and conmen" who exploit widely-held superstitions and the ignorant, particularly in rural areas.

In May this year, police said they had foiled an alleged attempt to abduct and kill a seven-year-old girl in a village near Nashik, northwest of Mumbai, as part of a ritual to find hidden treasure.

And last year, a childless couple in a remote village some 675 kilometres (420 miles) east of Mumbai were arrested for allegedly killing five young boys because a religious mystic told them it would help the woman to conceive.

Practices to be banned by the proposed law include beating a person to exorcise ghosts or making money by claiming to work miracles.

Treating a dog, snake or scorpion bite with chants instead of medicine, and seeking sexual favours by claiming to be an incarnation of a holy spirit or the client's wife or husband in a past life would also be proscribed.

Some critics, however, say the draft law does not go far enough and has been watered down since it was first mooted way back in 1995 due to protests from pro-Hindu groups.

"In my opinion the bill that has ultimately come into Maharashtra suggests nothing new. It doesn't give anything additional," said Sanal Edamaruku, president of the Indian Rationalist Association.

Concerns about the draft law's impact on legitimate religious practices from Hindu nationalist groups such as the Shiv Sena in Maharashtra and the Bharatiya Janata Party (BJP) have delayed its passing.

They say it could be used to prevent common Hindu rites like the "havan" ritual, in which a consecrated fire is lit in the home to chase away evil spirits.

Dabholkar rejects the charge that the bill is anti-religion.

"In the whole of the bill, there's not a single word about God or religion. Nothing like that. The Indian constitution allows freedom of worship and nobody can take that away," he said.

"This is about fraudulent and exploitative practices."

For Edamaruku, whose organisation seeks to debunk superstition and promote scientific reasoning, a new India-wide law against charlatans is vital to build on the great strides made by the country in recent years.

Continued belief in superstitions and black magic "will hinder India's development," he said. "A countrywide law is needed. We need to fight against ignorance."