A pensioner who is suspected of shooting dead two women and four dogs, was known to the police.
The man, who was named by a source as breeder John Lowe, had previously been convicted of illegal puppy farming several years ago, according to a source.
The 82-year-old was arrested on suspicion of murder on Sunday by Surrey Police who received a call from Keepers Cottage Stud in Waverley Lane, Farnham, at about 10am.
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The body of a woman in her 60s was found inside the property while the body of a woman in her 40s was found outside near animal pens to the back of the house.
The women have not been formally identified but they were related and known to Mr Lowe.
Officers attempted to resuscitate the women but to no avail, police said.
Three German shepherds and a labrador were also shot and were removed from the property by the RSPCA, which also rescued a number of other animals.
Detective Chief Inspector Mark Preston, from the Surrey and Sussex major crime unit, said the motive for the killings would form part of the investigation and only one long-barrelled weapon had been found at the house.
Mr Preston said the younger woman's body was removed from the property on Sunday while the body of the older woman was taken away by a private ambulance on Monday afternoon.
He would not confirm who made the initial call to the police but said the suspect was uninjured and remained calm when officers attended the house, which is surrounded by dense woodland and has signs along the driveway which say 24-hour CCTV surveillance is in operation.
No one else was at the property at the time.
Mr Preston said: "It does appear to be a very contained incident.
"We can confirm that the officers also found one weapon, which is in the process of being recovered."
Mr Preston said he could not say whether the gun which was found was legally owned but confirmed that police had had dealings with the pensioner in the past and that the matter has been referred to the Independent Police Complaints Commission (IPCC).
Mr Preston added that he did not believe there were any active investigations in relation to the suspect at the time of the alleged shootings.
He said post-mortem examinations on the two women had begun this afternoon and police investigations were likely to continue at the property until the end of the week.
He said officers would be asking magistrates to extend the custody time limit so they could question the suspect further.
The RSPCA also confirmed it would be removing more dogs, cats and horses from the stud farm.
A spokeswoman said: "We are aware of the situation and working with police to ensure the welfare of the animals involved.
"We can confirm there are a number of animals at the property and will update people on the situation as soon as we can."
Neighbours could not shed much light on Mr Lowe's past but said dogs could always be heard barking.
In 2004 Mr Lowe was the subject of an investigation by BBC's Inside Out programme, which claimed that he was breeding scores of dogs and selling puppies in poor condition.
A spokesman for the IPCC confirmed they were aware of the incident and would be looking into it to make a decision about whether they will investigate the matter.