An 85-year-old woman was assaulted by a conman posing as a water company official who tricked his way into her home.

The man called at the house in Oxleay Road, Rayners Lane, 11.15am on Tuesday last week and said he had to check her radiators. She let him in and he asked her to go into the kitchen and turn on the taps, while he went into the living room.

When she returned to check how he was getting on, he grabbed her handbag from a side table and barged past her, sending her crashing to the floor as he fled the house. It is believed he got into a blue saloon car parked in nearby Alexandra Avenue.

A neighbour saw the commotion and found the pensioner lying helpless in her hallway and called the police and an ambulance. She was taken to Northwick Park Hospital where doctors discovered that she had broken her hip.

Sgt Matt Andrews of Harrow police said: "We are treating this as a very serious assault. A broken hip can be fatal in an elderly person as it takes a long time to heal and can lead to all sorts of illnesses, including pneumonia.

"Hopefully, this victim will be OK, but she is likely to be in hospital for weeks and have limited mobility for even longer. I would appeal for anyone with any information to come forward so that the people responsible can be caught."

The conman was white, 35, 5ft8, with short, dark brown hair, and wearing a beige jacket. His driver had short, blond hair and was wearing a denim jacket. Witnesses are asked to call DC Bob Sheriff on 020 8733 3432.