Police in the UK have identified a number of people living in Ireland who they want to question about the suspected ritualistic murder of an African boy whose torso was found in the River Thames, London, in September 2001.
The child was never identified but the torso is believed to have been that of a male aged between four and seven. He was given the name Adam.
A file is being prepared for the UK's Crown Prosecution Service, an indication that the police there may be about to bring charges, or extradite suspects, from a number of countries.
Last July a Nigerian national, Samuel Koulibaly (37), who is also known as Samuel Onojighovie, appeared before the High Court in Dublin on foot of an extradition warrant to Germany.
Koulibaly was wanted in Germany in connection with alleged fraud and forgery. At that time the UK authorities said they wanted to question him about the torso discovered in the Thames.
London's Metropolitan Police yesterday said they had made a significant breakthrough in the case. A substance found in the boy's stomach has been identified as ground calabar beans, which have been used in parts of Africa to poison people suspected of being witches.
Cmdr Andy Baker of the Metropolitan Police told Sky News that officers working on the case now wanted to interview a number of people currently living in Ireland.
"We are putting together an advice file now on the circumstantial evidence we have got so far. We are very optimistic, we will not give up, we are determined," he later told BBC Radio 4.
"We must keep an open mind. It could be that the motive was purely domestic. But we do believe 99.9 per cent it was of a ritual nature, it was very macabre, extremely violent."
A spokesman for Scotland Yard said while detectives had visited "Ireland and other countries" he could not say when, or if, anybody residing in Ireland would be extradited to the UK.
The office of the British Attorney General, Lord Goldsmith, yesterday issued a statement saying he had "expressed an interest in leading for the prosecution in this case".
"Not just for Adam's sake, but - if he was a victim of trafficking - to send a clear message to those who deceive, coerce or force vulnerable people to leave their homes for a life of exploitation and misery or worse, that they will not escape justice."
It would be the first time in modern British history that an attorney general has been the lead prosecutor in a criminal trial, his office said.
British police have always suspected Adam was taken from Africa to London, and then murdered in a ritual killing. They also believe the murder was not the work of one person acting alone.
A post-mortem revealed Adam died from a massive trauma to the neck and that he had been in the Thames for up to 10 days before being discovered.
