The grandfather of the missing child Ben Needham has returned to the Greek holiday island of Kos to help police with their search for his missing grandson.

Investigators are using police dogs trained to detect human remains.

Ben's grandfather Eddie Needham, now 63, and his wife were taking care of the child when he disappeared in 1991 from the farmhouse on the island that the family then owned. Ben was just 21 months old when he disappeared.

Ben was playing outside with a stick and was poking the mud and throwing water over himself, Needham told the Daily Mirror.

"The biggest thing that's haunted me is I used to hear him in my head. 'I'm here grandad. Come and find me. I'm here.'

"I searched everywhere - the ravine, the brambles, the outbuildings, the well."

"I had to give up searching for Ben for my own sanity. It was sending me mad. I couldn't think or operate properly."

The child was previously thought to have been murdered or abducted. Police are now examining a theory that the child might have been accidentally buried beneath rubble near a building that was under renovation.

The British team, which includes a forensic archaeologist, is to continue the search for at least ten days. The team is led by Det Sup Matt Fenwick of South Yorkshire Police.

So far, no trace of the boy has been found.