• Picture of Papayo’s mother Sally Kalokoh / BBC.

With many families left traumatised by killings apparently linked to supposed magic rituals in Sierra Leone, BBC Africa Eye looks into those behind the trade in human body parts.

The mother of an 11-year-old boy murdered as part of a suspected black magic killing four years ago is devastated that no-one has yet been brought to justice for his death.

“Today I’m in pain.They killed my child and now there is just silence,” Sallay Kalokoh told BBC Africa Eye, explaining how her son Papayo was found with parts of his body removed, including his vital organs, eyes and one arm.

He had gone out to sell fish at the market and never came back.His family searched for him for two weeks – and finally found his mutilated corpse at the bottom of a well.

“We always tell our children to be careful. If you are selling, don’t go to a corner or take gifts from strangers. It happens frequently in this country,” Ms Kalokoh said.

This murder in my hometown of Makeni, in central Sierra Leone, has haunted me as we often hear of reports of killings linked to black magic, also known as juju, that are never followed up or properly investigated by the authorities.

In Papayo’s case, the police did not even confirm that it was a “ritual killing” – when a person is murdered so that parts of their body can be used in so-called magic rituals by illicit juju practitioners.

They promise things like prosperity and power to clients who pay large sums in the false belief that human body parts can make such charms more potent

.But with the authorities severely under-resourced – there is only one pathologist in a country that has a population of 8.9 million – it is often impossible to gather the evidence needed to track down the culprits.

Belief in witchcraft is also so deeply ingrained in Sierra Leone, even among many police officers, that there is often a fear of pursuing cases further – and most go unsolved.

Our BBC Africa Eye team was able to find two people who claimed they were juju practitioners and offered to obtain body parts for ritual purposes.

Both said they were part of much larger networks – and one boasted that he had powerful clients across West Africa.

The BBC was unable to verify these claims.

One member of our team went undercover, using the name Osman, to pose as a politician who wanted to achieve power through human sacrifice.

We first travelled to a remote area of Kambia district, in the north of the country near the Guinean border, to meet the juju man in his secret shrine – an area in dense bush where he consulted with his clients.

“When Osman specified that he wanted limbs from a woman to be used in a ritual, Kanu got down to business: “The price of a woman is 70m leones [£2,500; $3,000].”

Calling himself Kanu, he wore a ceremonial red mask covering his whole face to conceal his identity and boasted of his political connections.

“I was working with some big, big politicians in Guinea, Senegal and Nigeria. We have our team. Sometimes during election time, at night, this place is full of people,” he claimed.

Election season is regarded by some as a particularly dangerous time when parents have been warned to take special care of their children because of the heightened risk of abductions.

On a second visit, Kanu became more confident and showed Osman what he said was evidence of his trade – a human skull.

“You see this? This belongs to someone. I dried it for them. It is a woman’s skull. I am expecting the person to pick this up today or tomorrow.”

He also pointed to a pit behind his shrine:

“This is where we hang human parts. We slaughter here, and the blood goes down there… Even big chiefs, when they want power, come here. I give them what they want.

“When Osman specified that he wanted limbs from a woman to be used in a ritual, Kanu got down to business: “The price of a woman is 70m leones [£2,500; $3,000].”

Anxious not to put anyone at risk, we did not meet Kanu again. He may have been a scammer, but we handed over our evidence to the local police to investigate further.

Such juju men sometimes refer to themselves as herbalists, the name given to healers who use traditional medicine often made from local plants to treat common illnesses.