Ben Needham disappeared from Kos in July 1991.

The mother of toddler Ben Needham, who disappeared on a Greek island in 1991, has issued a heartbreaking message on what would be his 35th birthday.

The Sheffield toddler was 21 months old when he disappeared without trace from outside a farmhouse on Kos.

He’d been taken there by his grandmother Christine to visit her husband Eddie, who was helping renovate the building in the remote hamlet of Irakles.

The family, including Ben’s mum Kerry, had moved to the island earlier in the year to start a new life.

Since the disappearance on July 24, 1991, the family has never rested in their search.

A major excavation took place on Kos in 2016Credit: PA

Kerry Needham told ITV Calendar News: “A birthday should be a day for celebration but every year I spend the day thinking where are you? What more can I do to find you?

“I wish someone would just have a heart and come forward with the information I desperately need.”

The 21-month old was living on Kos with Kerry and her family, who had moved from England earlier in 1991 to start a new life on the Greek isle.

On the morning of Wednesday July 24th, 1991, Kerry – who was only 19 years old herself at the time – was working at a nearby hotel while her dad Eddie was helping local workmen renovate a derelict farmhouse in the remote hamlet of Irakles. The farmhouse is reached via a single-track dead end road, with just a handful of homes making up the tiny community.

Kerry’s mum Christine decided to take Ben in a push chair from the caravan in which they were living nearby, to the farmhouse, to see Eddie.

Ben was playing with toy cars outside in the afternoon when the couple realised he wasn’t there. All that was left was a pair of his shorts drying on a tree.

There has been not a single confirmed sighting since, with the family spending decades on the search for the little boy who vanished into thin air.

After the initial search, and suspicion on the family which delayed investigations, the family returned home penniless and had to start their lives again.

In July 2011, 20 years after Ben’s disappearance, ITV Calendar producer Mark Witty persuaded a major Greek television programme to feature Ben’s case, in an attempt to find the truth. “Light at the End of the Tunnel” broadcast the first appeal that year – and has continued to support the search for Ben when new lines of inquiry emerge.

South Yorkshire Police received Home Office grants to carry out two excavations at the farm – in 2012 and 2016 – but despite a huge effort, involving Greek volunteers, nothing was found to conclusively prove Ben’s whereabouts.

At the end of the three-week 2016 excavation, South Yorkshire Police announced it was their professional opinion that Ben had died on the the day he disappeared, in an accident with a digger, which was being used nearby.

The family of the digger driver, Konstantinos Barkas, who died in 2015, vehemently refute the allegation. There have been numerous claims over the years from people claiming to be Ben, all of whom have been DNA tested and disproved.

Kerrie and Eddie travelled with ITV Calendar to Greece to follow up on some leadsCredit: ITV Calendar

In September 2011 Calendar’s Mark Witty and cameraman Simon White travelled with Kerry and Eddie Needham to the Albanian border with Greece, to follow up information on a man suspected of being Ben. He agreed to a mouth swab which was handed over to South Yorkshire Police at Manchester Airport. It was negative.

In 2015 a man came forward in Thessalonika, Greece, who was also convinced he was Ben. Mark and Simon travelled with Kerry, her mum Christine and daughter Leighanna to meet him – but their hopes were dashed when a DNA test proved no link.

Only this year a Danish man came forward believing he was the missing boy – but yet again there was no match.

Many other claims and messages go un-reported with most going direct to a small dedicated team which runs facebook.com/helpfindben

The social media page has attracted thousands of messages over the years, some of which have been investigated by them and ITV Calendar together, with updates sent to police where necessary.

Kerry added: “There are some people on Kos that definitely know what happened to Ben and I don’t know how they can sleep at night knowing the torment I go through year after year. I will never give up searching for the truth even if it kills me , we deserve to know the truth”