Nine fire crews from Sawtry, Kimbolton, Stanground, Huntingdon, Oundle, St Neots, Yaxley and RAF Molesworth were called to a farm in Church Lane, Winwick, at 4.27pm. No-one had been in the detached farm house, measuring 25 sq m, at the time of the fire. The fire took four hours to extinguish and has made the building structurally unsound. Most of the roof has been destroyed by the fire. A spokesman for Cambridgeshire Fire and Rescue Service said: All crews had left the scene by midnight and one crew from Huntingdon remained on site overnight continuing to dampen down any remaining hotspots. A fire investigation is underway to determine the cause of the fire. Early indications show there are no suspicious circumstances.