The boy, whose family were from Africa, had been taken into care by Islington council in north London.
His mother, who no longer had responsibility for her child, asked for him to be sent to the Democratic Republic of Congo for “deliverance”.
The boy’s family claimed this was necessary because they believed he was possessed by “kindoki” or evil spirits.
Islington social services officials then paid more than £4,000 for an expert to travel to Africa to investigate.
The expert, Richard Hoskins, an academic specialising in African religions, was alarmed by what he saw on the visit, and advised the council that the boy should not be exorcised.
After receiving his report, the council—then under Liberal Democrat control—abandoned the plan.
Dr Hoskins said that prior to his trip, some Islington council officials had been “mindful to agree to the request” for exorcism.
Speaking at a conference yesterday, he said the case demonstrated how officials in Britain were reluctant to challenge the mistreatement of children when it was committed under the guise of “religious or cultural practices”.
“This problem is about the underlying failure to tackle abuse when it is masked behind multiculturalism,” he said. “We fear to trend where sensibilities might apparently be affected.”
During his visit to Kinshasa, the capital of the DRC, in 2005, Dr Hoskins met the grandparents of the boy at the centre of the case. They told him that the child had been “infected by sorcery” while in the UK and that he “would destroy them all”.
The deliverance that the boy was to undergo would have involved starving him of food and fluids for three days.
At the end of the fasting period, he would be surrounded by the deliverance team who would pray over him and command the evil spirit to be cast out of the child. When deliverance takes place, the child vomits up the “sorcery bread” that has been infecting him.
Dr Hoskins also met the pastor from the Pentecostal church attended by the grandparents, who warned that if the evil spirits were not dealt with, they would cause “strife, illness, divorce, hardship, poverty and death”.
The pastor claimed that the boy would have sorcery tools to perform magic with, such as mirrors, brushes, sticks and string, and warned that these would have to be confiscated.
Dr Hoskins asked whether the boy would be beaten, and was assured that this was not part of the normal deliverance process. However, when he was presented with a boy who had recently undergone the ordeal, he found the child “scared and traumatised”.
Islington paid £4,372 to fund the trip, including Dr Hoskins’s fee of £3,080, half of the cost of the £710 flight, taxi fares, accommodation and refreshments bills.
In his report to the council, the academic wrote: “Whilst I found the family and the church to be very friendly, I cannot recommend that the child be allowed to go through a deliverance service such as that envisaged.
“From my research I think this might be deeply disturbing and traumatising for him.”
Speaking yesterday at the education conference at Wellington College, in Berkshire, Dr Hoskins, a research fellow in criminology at Roehampton University, said: “These deliverances can be very violent.
“In one case I met a girl at death’s door because the pastor had not let her drink for days despite the tropical heat.
“Children are often shaken, beaten and sprayed with chilli peppers. They are sometimes even cut with razor blades.”
Witchcraft or “kindoki” is a widespread belief in parts of central and western Africa and in the DRC in particular. It is not uncommon for children to be accused of being witches and have to endure exorcisms.
The Islington investigation followed high-profile cases in which children born in Africa, or of African heritage, living in the UK had been abused or killed by relatives who believed they were possessed.
In 2000, Victoria Climbié, eight, from the Ivory Coast, was tortured and murdered by her great aunt and her boyfriend in Haringey.
Three years later, the mother, aunt and uncle of an eight year old girl in Hackney were sent to prison for between four and ten years for a “campaign of torture” against her. In both cases the victims’ relatives claimed they were witches.
More recently, Kristy Bamu, a 15 year old from France, was tortured to death by his sister and her boyfriend in an increasingly extreme “deliverance” in a flat in Manor Park, east London, when the teenager refused to admit to sorcery and witchcraft.
Despite the high-profile cases, social services are failing to tackle the problem because of misguided political correctness, according to Dr Hoskins.
The academic, who gave evidence earlier this year at the Kristy Bamu murder trial, is also the author of The Boy in the River, which explores the unsolved case of “Adam”, a young black boy whose mutilated torso was found floating in the Thames in 2001.
Dr Hoskins said he was currently working on a case where a teenage girl, born in the UK of African descent, had been removed from her family following a violent “deliverance” in which she was hit with sticks, cut on her arms with a knife and had chilli pepper rubbed into her eyes and genitalia.
She was placed by social services in the temporary care of her pastor, who had promoted the use of the exorcism and then put pressure on the child to withdraw all evidence.
“Some women and children from diverse cultural backgrounds are suffering horrendous abuse, and even death, because authorities are too afraid to intervene,” Dr Hoskins said.
“There is growing evidence that all manner of evils are being committed in the name of cultural beliefs and practices that should play not part in contemporary Britain.”
Islington council acknowledged it had paid Dr Hoskins to travel to Africa, but claimed it was on the instruction of a judge.
“It is a normal process in care proceedings to assess the extended family when a child has been removed from parental care,” a spokesman said.
“Dr Hoskins was instructed to meet with extended family members to assess their belief that a child of the family was possessed by spirits. This was on the instruction of the Family Court during care proceedings.”
The council said it could not disclose the court order. Dr Hoskins said he had never been aware of a court order asking for the visit to be arranged.
A spokesman for the Department for Education said: “It is not acceptable for councils to be considering this. These services can be extremely traumatic. We are tackling all forms of child abuse linked to belief, including belief in witchcraft or spirit possession.
“Such abuse is rightly condemned by people of all cultures, communities and faiths.
“Local authorities and voluntary, community and faith organisations are working together with the Government to understand faith-based child abuse better, raise awareness of this issue among professionals and the public, and support communities to tackle this form of child abuse.”