The sheet was found in the river Thames
Detectives revealed on Friday that a world expert in so-called "muti" killings will carry out a post mortem on the body next week.
Evidence uncovered this week on the southern shore of the Thames has provided further indications that the boy was killed in this way.
He could be the first person in the UK to die in a "muti" killing, which is known to have been practised in South Africa.
It was revealed on Friday that detectives have found seven half-burned candles wrapped in a white sheet washed up on the southern shore of the River Thames in London.
A name - Adekoye Jo Fola Adeoye - was written on the sheet and the name Fola Adeoye inscribed on the candles.
South African pathologist Professor H.J.Scholtz, a world expert in muti/ritualistic murders, will present the findings of Monday's second post mortem to a special police conference on Tuesday.
The boy's torso, wearing orange shorts, was spotted floating in the Thames by a man walking across Tower Bridge on 21 September last year.
It is believed the body had been in the water for up to 10 days.
Forensic experts estimate that the boy, who was of Afro-Caribbean origin, was aged between five and six.
Detectives have since taken the unprecedented step of giving him a name, "Adam".
A national appeal for information followed the discovery, but although this generated a huge amount of publicity, officers still have not been able to identify the body.
A £50,000 reward has been offered for information leading to a conviction for the boy's murder.
On Wednesday Commander Andy Baker, of the Met Police Serious Crimes Group, said: "Until we can identify him and his family, we will act as his family.
"And to remind everyone that he was a person, we decided to give him the name Adam."
He said establishing Adam's identity would be a big step towards finding his killers.
Detectives suspected the murder may be connected with a witchcraft ritual, in October last year.
During the investigation, officers have consulted with Dutch police about another probe into the death of a girl, whose body was left in a similar state.
No formal link, however, has been established between the two cases.