AN elderly man is recovering at his home after an unknown attacker sprayed him in the face with a mystery substance that left him needing hospital treatment.

The incident happened after the 70-year-old victim heard a noise at the rear door of his home in The Dene, Consett at around 7.35pm on Thursday night.

He was alone as his wife had gone out a short time earlier.

When he opened the door he was confronted by a masked figure, aged in his late 'teens or early twenties, dressed in black.

Without any warning the figure then sprayed the pensioner in the face with a liquid which smelled like ammonia. Fortunately he was wearing his glasses, which kept the fluid out of his eyes, but enough went around his face and inside his mouth to cause minor burns and some difficulty with his breathing.

After being treated at the University Hospital of North Durham the victim, who is not being identified, was allowed home.

Detective Constable Catherine Knox said: "This is a shocking incident and the gentleman concerned has no idea who could have done this.

"We have been conducting enquiries in the area and would urge anyone who thinks they know who could have been responsible to come forward."

Callers can contact Consett CID on 0345-60-60-365 or Crimestoppers on 0800-555-111.