Armed police are said to have stormed the house where a woman was found stabbed to death in Wandsworth, according to a neighbour.

Police and paramedics raced to a flat in the affluent 'Nappy Valley' area of Lavender Hill at lunchtime today but they were unable to save the woman who was pronounced dead at the scene just before 1.45pm.

A 40-year-old man was arrested at the scene on suspicion of murder and was "calm" when arrested, according to eye-witnesses.

A neighbour said: "My wife and I saw armed police break down the door and enter the house.

"We originally thought someone had been shot. One police officer left holding a small stepladder.

"We have two young children so we're glad it wasn't a shooting.

"It's very quiet around here - you wouldn't expect this."

Another resident said he saw police then leave the house with a folding stepladder.

The end of terrace house in the well-heeled Lavender Hill area has been cordoned off while police investigate.

Clusters of people watched from the edges of the cordon - some with children in buggies and in their arms.

An empty ambulance was seen within the cordon, with an empty stretcher positioned alongside it on the pavement.

Anther neighbour said she saw a 'coloured man' being taken away in handcuffs.

UPDATE 16/08: A neighbour had previously been quoted as saying the emergency call had been first made by a six-year-old boy. Met Police have since confirmed this is incorrect, and that the call to police was not made by a child.