The hunt for Nigerians who can change into cats

Gbenga Adewoyin could have passed for a medieval witch hunter as he walked around a market in the south-western Nigerian city of Ibadan.

"Anyone that can provide any evidence for the existence of the supernatural, be it juju or voodoo magic, will be offered 2.5m naira ($6,000, £4,650)," he announced repeatedly. "The knife is for anyone that claims their juju makes them blade-proof."

The 24-year-old atheist has recently emerged as a rebel publicly contesting the powers of the supernatural in this deeply religious country.

Many Nigerians believe that magic charms can allow humans to morph into cats, protect bare skins from sharp blades and make money appear in a clay pot.

Dr Olaleye Kayode, a senior lecturer in African Indigenous Religions at the University of Ibadan, told the BBC that money-making juju rituals - where human body parts mixed with charms makes money spew out of a pot - really work. The naira notes that supposedly appear "are gotten by spirits from existing banks."

Jude Akanbi, a lecturer at the Crowther Graduate Theological Seminary, is also unequivocal about juju.

"This ability to be able to transform yourself to [a] cat, to disappear and reappear, these things are possible within the dynamics of traditional African religion. It sounds illogical, however from what we have seen and heard, these things are possible," he said.

Such beliefs, especially that human body parts and charms can produce money from a clay pot, have led to a recent wave of gruesome murders in the country, with single women often the victims. Hardly a day passes without reports of a missing person and pictures of mutilated corpses linked to juju.

There was widespread outrage last month after three men killed a 17-year-old girl in Ogun state to use her body parts in a ritual they believed would make them rich.