THE FIVE-YEAR-OLD African boy whose torso washed up in the River Thames in September, was the victim of a voodoo ritual in which his body parts were used in potions aimed at achieving supernatural powers, detectives confirmed this week.

A second postmortem was carried out on the remains of the boy, who police believe may have been thrown into the Thames at Chiswick, and pathologists revealed that the child was killed as a sacrifice in a ritual murder.

South African pathologist, Professor Hendrik Scholtz, told a conference of senior detectives on Tuesday that those who killed the boy almost certainly made potions from parts of his body in the hope of achieving supernatural powers.

The world expert in such murders said: The brain and skull are used in the preparation of potions which are then taken. By a person's sacrifice they believe they can awake the supernatural forces required to attain the goal required.''

He said such killings were carried out in Africa by people trying to achieve business prosperity or high political office. The murder was almost certainly the act of a group, he added.

Prof Scholtz carried out a second postmortem on the boy - named Adam by police - on Monday working with Dr Mike Heath, who performed the first postmortem.

The National Crime Faculty at the Police College at Bramshill hosted the subsequent conference where police experts and partner agencies received presentations and discussed the murder in detail.

Detectives leading the inquiry - the first of its kind in Britain - renewed their appeals for information by releasing a silhouette of Adam. The move follows an increase in reward money to £50,000 for anyone who provides information on the circumstances surrounding his death.

Det Insp Will O'Reilly, leading the inquiry, appealed for anyone who knew the boy to come forward, and added: You may be a sister, brother, parent or other relative. You may be a friend or neighbour. Did you know a young child like Adam, but have not seen him since September? Are you his teacher or carer but have not seen him? I am also appealing for anyone who may have seen anything suspicious near the Thames shoreline or embankment or any of the bridges crossing the river up to a week before Adam was seen in the river to come forward.''

Adam was described as well-nourished and could have been in the water for up to ten days. He was dressed in a pair of orange shorts which are sold in outlets of Woolworths in Germany and are made for girls, not boys. Police are also appealing for anyone who recognises them or who may know anyone who wore them to come forward.

Anyone with information should contact police on 8853 1212, or call crimestoppers anonymously on 0800 555 111.