A team of British police officers are to examine a mound of land on the Greek island of Kos, close to where toddler Ben Needham went missing 21 years ago.
The officers are leading a group of specialist search advisers who will be supporting the Greek authorities as they decide whether to excavate a particular mound of earth.
Ben, who was born at Boston's Pilgrim Hospital, was 21 months old when he vanished from the island on July 24, 1991, close to an old farmhouse which was being renovated by his grandparents.
Last year, South Yorkshire Police went to the High Court to get a sample of Ben's DNA, taken during the routine Guthrie heel-prick test, in order to cross-check it against databases held in other countries.
Despite a number of possible sightings and a range of theories about what happened to him, no trace of the youngster has been found.
His disappearance sparked an international hunt, with the Greek police alone logging up to 200 possible sightings of the missing child.
In the months and years after he disappeared, the most common theory was that he had been snatched by Gypsies.
It has also been suggested that Ben, who would now be 22, was taken for adoption by a non-Greek family, perhaps in Australia or the United States.
His mother, Kerry Grist-Needham, from Sheffield, has always believed he was abducted and is alive.
Mrs Needham, 41, told the Daily Mirror: “This is an elimination process and that’s how I’m dealing with it. It’s one of the most important things to happen in 21 years.”
The police operation is expected to last a week to 10 days.