Stabbing victim: Accountant Sonita Nijhawan, 38

A four-year-old boy is believed to have witnessed an attack in which his mother was stabbed to death and his father seriously injured at their home near an exclusive estate known as 'Britain's Beverly Hills'.

Police who rushed to the £2million house near the gated community of St George's Hill in Weybridge, Surrey, yesterday are understood to be treating the tragedy as a murder and attempted suicide after the woman in her 30s was stabbed and strangled.

The emergency services were confronted by a horrific scene after being alerted by worried relatives of the woman.

A man believed to be her husband was allegedly seen slashing at his own throat and arms with a knife and was rushed to hospital for treatment.

His injuries were so severe

Neighbours said the couple had a four-year-old child who was seen being carried away from the scene.

The couple, named locally as accountant Sonita Nijhawan, 38, and her investment banker husband Sanjay, 46, had only just moved into their newly completed dream home, after knocking down a smaller property on the site which they bought for £925,000 in 2009.

It emerged today that Mrs Nijhawan had been strangled as well as suffering several stab wounds and was found lying surrounded by a huge amount of blood.

Residents in the upmarket commuter belt area then heard an air ambulance hovering overhead and the man was taken to an undisclosed hospital where it is understood police remain on guard.

The couple had been living at Sonita's parents home in Hampton, London, until this spring when their new home was ready to move into.

Sonita was the director of three care homes in Surrey and is in business with her father Chander Parkash and brother Amit.

The care home, some with specialist dementia care, she owned include The Cedars, Pantiels and Springfield Care Homes under the umbrella company of SPC Care Homes.

Forensic detectives were seen going into the £2million mansion today to examine the scene

The body of the woman, 38, was found at a house in the upmarket St George's Hill area of Weybridge - dubbed Britain's Beverly Hills. Pictured are forensic officers at the home today

A police officer and forensic detectives are seen working outside the house in Weybridge

A neighbour, who did not want to be named, told The Mail on Sunday: 'Sonita and Sanjay seemed like a really lovely young British Indian couple. They only moved into the house about a week ago – but it was under construction for about two years.

'I had several conversations with them over the past few days, the last one just last night.

'Everything seemed absolutely fine. They just seemed relaxed. They were a rich couple – Sanjay worked in the City. He was quiet, sweet and soft-spoken. You couldn't imagine him hurting anyone.'

The neighbour said she spoke to Sonita's father yesterday morning after he had been into the house where the killing took place.

She said: 'He told me that police believe it was a murder-suicide attack. Their four-year-old boy was in the house and witnessed the attack and was left in there until the police and ambulance service arrived. The boy was then taken away.'

Police rushed to the £2 million house near the gated community of St George's Hill in Weybridge, Surrey, where Sonita's four year-old-son reportedly saw her being stabbed to death

A man believed to be her husband was seen 'slashing at his own throat and arms with a knife' and was rushed to hospital for treatment

A neighbour who lives next door to Sonita's parents' home in Twickenham, South-West London, said: 'Sonita was completely lovable. She was a beautiful girl, a kind person and a loving mother.

'She got married six years ago. They had the wedding in a tent behind the house. The family come from a strong Hindu background and the ceremony was very traditional.

'Her father, mother and brother will be absolutely devastated by the loss.'

Crime scene officers were expected to be at the house throughout the rest of the day gathering evidence

The estate known locally as 'The Hill' has exclusive grounds with a private members golf and tennis club

A spokesman for Surrey Police said a man had been taken to an undisclosed hospital with serious injuries. He has been arrested on suspicion of murder.

The Surrey and Sussex Major Crime Team said the investigation was in its early stages, but they did not believe anyone else was involved in the tragedy.

Detective Chief Inspector Jason Taylor said: 'I believe this to be an isolated incident, with no wider threat to the local community.'

Exclusive enclave of gated estates that's home to some of Britain's biggest names

The shocking killing took place in an area that has for decades been a place of sanctuary for the rich and famous.

The tragedy happened in a house on a gated private road adjacent to exclusive St George's Hill, whose residents have included John Lennon, Ringo Starr, Kate Winslet, Sir Cliff Richard and Sir Elton John.

It has also attracted footballers John Terry and Peter Crouch and his model girlfriend Abbey Clancy.

The shocking killing took place in an area that has for decades been a place of sanctuary for the rich and famous, with residents including Peter Crouch and Abbey Clancy (left), and The Beatles star John Lennon

The estate, built in the 1920s and known locally as The Hill, has its own residents' association and within its 964-acre grounds are a private members' golf and tennis club.

It describes itself on its website as 'a distinctive and unique location designed for driven, motivated and successful high-achievers looking for a secure and private location in tranquil surroundings. The Hill is a place that provides an escape from the busy lives of its discerning residents.'

Houses on the complex and in the surrounding streets change hands for up to £13 million.

John Lennon's mansion on the estate, where he wrote the Sgt Pepper's album, is up for sale - for a staggering £14 million

Bollywood actress Shilpa Shetty and Dragons' Den star Theo Paphitis currently live at The Hill and recently hedge-fund managers, Russian oil barons and City financiers have moved in, attracted by the privacy and apparent safety.