Detectives investigating the disappearance of Ben Needham from Sheffield have revealed a mystery caller told police his name has been changed to Andreas.
Ben was 21 months old when he disappeared on the Greek island of Kos in July 1991.
At a South Yorkshire Police press conference on the island this morning detectives revealed that a mystery caller contacted police in 1993 claiming that they knew where Ben was and that his name had been changed to Andreas.
They said he was being cared for by a man called Nikos.
Detectives want the caller to get back in touch.
Detective Inspector Jon Cousins said: "In 1993, someone rang a missing persons helpline and specifically said Ben was known then as Andreas.
"He also said Ben was being cared for by a man known as Nikos. I would like the perspn who rang that helpline to come forward and speak to us again.
"I appeal to any individuals who believe they might be Ben themselves to come forward and speak to us.
"There will be no pressure on them at all - we have Ben's DNA and it's very easy for us to do a quick test and either confirm or otherwise whether that person might be Ben.
Detective Superintendent Matthew Fenwick added: "Twenty-five years ago, Ben Needham went missing from this very spot. We've been over to Greece on a number of occasions to appeal to the Greek people regarding what happened to Ben.
"I believe that it's highly likely someone living on Kos today or somebody who has lived on Kos previously has the answers over what happened to Ben.
A £10,000 reward for information leading to the discovery of Ben is available.