British police are to help search land on a Greek island close to where Sheffield toddler Ben Needham disappeared 21 years ago.
Ben vanished on the island of Kos in July 1991, when he was 21 months old.
In May, his mother Kerry dismissed a report he could have died in a building site accident near the family's house.
Experts from police forces from across the UK have flown out to assist Greek authorities in their search of the area on Friday.
It is understood that Mrs Needham will arrive on Kos, supported by a police family liaison officer, during the search.
In a statement, she said she met the island's chief of police a year ago and was promised they were serious about reinvestigating her son's disappearance.
She said: "I am so pleased that this investigation is now moving forward and that the Greek authorities are showing a true commitment to investigate Ben's disappearance.
"Today is just a start, I understand that all possibilities have to be considered and the search of the area around the building work where Ben disappeared is part of that."
Dogs trained to search for human remains will be used during the search.
South Yorkshire Police said it was leading the team of "specialist search advisers" who had travelled to Greece.
The force said they would start work on Friday, examining the ground, using geophysical equipment, to determine whether any areas should be dug up.
A spokesman said: "Other specialist resources include a forensic archaeologist and search dogs.
"The operation, expected to last a week to 10 days, follows a Greek police request for specialist support to follow through a line of enquiry they have developed."
South Yorkshire Police has reviewed all material held by the Greek police in relation to Ben's disappearance over the past 18 months and obtained his DNA from Sheffield Children's Hospital.
In May the Daily Mirror reported that Greek police believed Ben may have been buried under rubble near the farmhouse.
The newspaper said Greek police wanted to excavate the now-overgrown mound of earth and rubble on a property neighbouring the farmhouse which Mrs Needham's father was renovating at the time of her son's disappearance.