Detectives investigating after a boy's torso was found in the Thames are examining claims human flesh is being offered for sale in London.

They believe the murdered five-year-old, who they have called Adam, was the victim of a ritualistic killing.

The boy's mutilated remains were discovered in the Thames near Tower Bridge last September.

Detectives from Operation Swalcliffe, which is looking into Adam's death, joined a raid on a north London shop last month by environmental health officers from Haringey Council.

Crocodile head

It followed a tip-off that human body parts were being sold.

Although no human remains were found several packages with unidentifiable meat have been sent away for DNA testing.

Environmental health officers did seize two tonnes of unfit meat, including a crocodile head and rat faeces, which had been removed from rats' intestines.

Police believe that Adam was brought to the UK as a slave and sacrificed in a ritual intended to bring good luck to his killers.

"There is an ongoing search for Adam's head and limbs and there is evidence to suggest a link between those who are involved and the trade in illegal animal parts and meat products, and that is why we took part in the raid in an observing capacity," a Metropolitan Police spokesman said.

Two officers are in Nigeria trying to find Adam's parents after DNA tests proved he was born there.