"I can't imagine how disturbed someone is." Police believe grandfather responsible for Margaret River shooting.

Police have confirmed three guns found at a rural West Australian property where seven relatives – including four children, were killed in a suspected murder-suicide belonged to the children’s grandfather.

While the bodies are yet to be formally identified, police on Saturday said they believe property owners Peter and Cynda Miles, aged 61 and 58, were among those found dead northeast of the popular tourist hub of Margaret River just after 5am on Friday.

The others are believed to be their 35-year-old daughter Katrina Miles and her four children – daughter Taye, 13, and sons Rylan, 12, Arye, 10, and Kadyn Cockman, eight.

All of the victims suffered gunshot wounds.

WA Police Commissioner Chris Dawson on Saturday said three firearms were found at the scene, all of which were licensed to Peter Miles.

“Police do not believe any other person is involved with these crimes,” he told reporters.

“Police are not searching for any other suspect.”

Commissioner Dawson said only one victim was found outside of the property’s buildings. One woman was found dead inside the main house, while another woman and four children were discovered inside a converted shed.

“The examination of the crime scene will still take several days,” he said.

Augusta-Margaret River Shire president Pamela Townshend said the people on Osmington Road were a tight sub-community and offered her condolences to the family.

“I’m absolutely devastated that this has happened in our community,” she told reporters.

“It’s such a small community and it will have a huge effect.”

With AAP. 

Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or Suicide Call Back Service 1300 659 467.

If you or someone you know is impacted by sexual assault, domestic or family violence, call 1800RESPECT on 1800 737 732 or visit 1800RESPECT.org.au. In an emergency, call 000.