POLICE investigating Sian O'Callaghan's death are using mechanical diggers to excavate the corner of a field in Eastleach in their hunt for a second body.

Around 15 officers and forensics experts are searching land at Baxter's Farm, between the villages of Eastleach and Filkins.

They have removed part of a dry stone wall and have excavated two trenches in the corner of the field, where officers in protective clothing were on their hands and knees in the mud.

DCI Sean Memory, who is leading the search, said officers had received "relatively specific" information from a man held in connection with the 22-year-old's death but that nothing had yet been found.

"We were given some indication of where there might be a find. Of course, it isn't as simple as that. It was tricky last night in the dark. We will use as much light as we can and then decide what we will do when it gets dark," he said.

Police have erected a blue tent in the field where they are searching.

DCI Memory said they had been searching since last night using powerful lights.

The farm at the centre of the search lies within rolling countryside a couple of miles south from the Cotswold Wildlife Park, outside the small market town of Burford.