A dog trainer who once worked for Princess Anne is suspected of murdering his wife at the cottage where Boris Johnson grew up.

John Zurick, 67, allegedly shot his estranged wife Debbie, 56, after he discovered she had a new boyfriend. He then turned the shotgun on himself, friends said yesterday.

Paramedics were called to the cottage, on the Prime Minister's family estate in Somerset, on Saturday afternoon but were unable to save Mrs Zurick.

Her husband was airlifted to hospital, where he remains in a critical but stable condition. The couple, who had been married for 30 years, bred and trained clumber spaniels.

A photograph on Mr Zurick's Facebook page from March 2016 appears to show Mr Johnson outside the cottage in Winsford, near Minehead, with one of the couple's dogs, also called Boris.

Pictured: Debbie Zurick and John Zurick. Neighbours of the couple, who lived in Nethercote Cottage, Winsford, Somerset, next to the Johnson family's 500-acre estate, say the couple's marriage was in crisis and Mrs Zurick had asked her husband for a divorce

Pictured: Debbie and John Zurick with their dogs. Police have opened a murder probe

Paramedics were called to the cottage, on the Prime Minister's family estate in Somerset, on Saturday afternoon but were unable to save Mrs Zurick (pictured)

The Zuricks bought the property, where the Prime Minister spent some of his childhood, from Mr Johnson's father Stanley for £440,000 in 2013.

Stanley Johnson owns the neighbouring 14th century farmhouse on the Nethercote estate with his wife Jennifer. A third house on the estate is owned by the Prime Minister's sister Rachel.

There are also a number of barns, which have been converted into properties, whose owners include Boris and his brother Leo.

The Zuricks were regulars at game shoots and were key figures in the Working Clumber Spaniel Society, of which Princess Anne is president.

On the society's website, Mr Zurick describes how he trained Anne's dog Sparkle but received a rebuke from the princess when the hound failed to bring back a pheasant.

Stanley Johnson told the Daily Mail last night: 'Both I and my whole family are shocked, stunned and saddened by this tragic incident.

A picture posted on the couple's social media showing Boris Johnson meeting their dog, also called Boris

'We very much regret the passing of Mrs Zurick. She was a neighbour and she was much loved.

'She was honorary secretary of the Working Clumber Spaniel Society and was much loved for the work she did, in the society and in Exmoor and beyond.' He declined to say whether his family had taken working spaniels from the Zuricks.

Friends of the couple said Mrs Zurick had become 'exasperated' with her husband and moved to a friend's house in Ireland 'to get away from it all'.

Mr Zurick had hoped for a reconciliation and was deeply upset when he discovered his wife had a new boyfriend.

Mrs Zurick, who is said to have been treated for cancer, is believed to have been shot when she returned to the cottage on Saturday with a female friend to collect some possessions and take care of the dog breeding business.

Officers were called to the property after reports of a hearing a gunshot in Winsford, Somerset

The Zuricks were regulars at game shoots and were key figures in the Working Clumber Spaniel Society, of which Princess Anne is president. Pictured John Zurick, second right

Firearms officers were despatched to the property at 2.30pm and found Mrs Zurick outside with severe injuries. Her friend was uninjured. Mr Zurick, who had suffered a shotgun wound, was in an outbuilding.

Last night Avon and Somerset Police said it had referred itself to the police watchdog over 'prior police contact with those involved'. A close friend of the couple told the Daily Mail: 'They split up a few months ago and Debbie went to live in Ireland to get away from it all. She was exasperated with their relationship.

'Debbie returned to the cottage because of the dogs and John had just found out about the new man in her life.'

One neighbour said: 'Debbie wanted a separation.

'Things came to a head over the last couple of weeks. I've been told that she's dead and that is such awful news – particularly as she seemed to be recovering well from cancer treatment.'

Neighbours of the couple, who lived in Nethercote Cottage, Winsford, Somerset, next to the Johnson family's 500-acre estate, say the couple's marriage was in crisis and Mrs Zurick had asked her husband for a divorce

Winsford borders Exmoor National Park and is home to a 12th century pub, The Royal Oak Exmoor

Another neighbour said: 'Debbie was popular around here. She lived for her dogs and she'd look after other dogs for friends.

'From what you hear they were friendly with the Johnsons, which is just as well as there's no other property for at least a mile in any direction.'

Mr Zurick developed an interest in shooting through his father-in-law and bought his first shotgun from him, friends said.

Mr and Mrs Zurick had no children. Mr Zurick's son from his first marriage died in 1995 aged 17.

Police have begun a murder investigation and are continuing to search the property but are not looking for anyone else in connection with the incident.

Detective Superintendent Julie Mackay said: 'This is a very serious incident in which a woman has lost her life. Due to prior police contact with those involved, a mandatory referral has been made to the Independent Office for Police Conduct.

'It would be inappropriate for us to go into further details while the referral is being considered.'

Mrs Zurick's half-brother Phillip Townsend told MailOnline last night: 'I've been told that Debbie is dead and John is in a bad way in hospital. The police haven't told us anything. We are just in shock, it's terrible.'