Ben Needham disappeared on 24th July 1991 when he was just 21 months old.
Ever since that fateful day her little boy vanished, Kerry Needham has campaigned tirelessly for police to continue investigating Ben’s disappearance.
Now, after securing £700,000 of Home Office funding, South Yorkshire Police are spending up to two weeks on Kos.
After landing on the Greek island, officers appealed for information about claims Ben may have been taken off the island and renamed Andreas.
They were then contacted by two sources, who alleged the boy was being cared for by a man called Nikos.
It wasn’t long before a photograph of a young blonde man, who lives on Kos, was posted on the 'Helpfindben' Facebook page.
The image was then passed onto South Yorkshire Police last week, who amazingly managed to track down the mystery man within four hours.
Police conducted DNA tests on the man, who was named Andreas.
However the results have since ruled him out of the investigation.
A South Yorkshire Police spokesman said: “One man’s DNA was taken by the team in Kos following information received via the Helpfindben page which suggested he could be Ben.
“Tests have confirmed that the man in question is not Ben Needham.
“The Operation Ben team will remain in Kos for another week exploring various lines of enquiry.”
Despite the initial setback, police have revealed that there is hope of a breakthrough in the missing child case.
They have received nearly 300 pieces of information relating to the case since landing in Kos.
And they are now following a new lead, in which a witness claims he saw Ben in July 1991 at a Roma camp in Samos island.
Detective Inspector Jon Cousins said previously: "[The Greek authorities] have given us every assistance that we require and that's allowed us to really progress this a lot further than where I thought we would be at this time.
"We're going to continue with our efforts looking in to everything that we have so far and, as we're going along, we're turning up new leads all the time that are very interesting to use.
"We're going to make sure that we pursue each and every one of those to try and find an answer for ourselves as well as for [Ben's mother] Kerry and the family."
Last year, Kerry penned a special open letter, which she hoped would be read by her son.
The letter, which was also translated into Greek on the Help Find Ben Needham website, reads: "This is a direct appeal to anyone who is around 25-years-old and possibly living with a family who you look nothing like, I beg you to get in contact with me.
"I promise to cause no problems for your family who you live with, I just want you to know the truth about what happened to you and to know you are healthy and happy.
"A simple DNA sample can be taken from you without causing any distress to anyone.
"So if you think you were born in 1989 and you have blue/grey eyes and a possible birthmark on your leg, YOU could be Ben!!!"
She continued: "Twenty-three years have gone by Ben and I love you just as much today as I did the day you were born.
"Please anyone get in touch and end all this pain your family feel living without you."