A blaze ripped through a barn in Oxford tonight, leaving the farm owner fearing he had been the victim of an arson attack.

About 400 bales of hay were found ablaze at Tilbury Farm, Botley, at 7.45pm, sending smoke billowing over the A34.

More than 20 firefighters tackled the blaze, which was likely to continue burning tomorrow.

William Barnett told police he threw out a homeless man who was sleeping in the barn on Tuesday night.

Officers were expected to stay at the farm throughout the night with tracking dogs. The force helicopter was scrambled, but no arrests had been made.

Mr Barnett said: "This is the second time in two months this has happened - I am absolutely gutted."

All farm animals were safely removed from the area and no-one was injured.

Didoct fire station manager Graham Turner said: "We quickly brought the fire under control, but it is expected to remain burning for a long time."

Sgt John Pennycook said: "At the moment, it is being treated as a fire of doubtful origin, with several thousand pounds' worth of damage."

Police have appealed for anyone who saw a man in the area, described as in his mid-50s, unkempt and unshaven and possibly wearing a hat, to contact 08458 505505 or Crimestoppers on 0800 555111.