The bodies of Maiwenna Goasdowe, 49, Jarrod Clune, 50, and their teenage sons Leon, 16, and Otis, 14, were found at their Mott Close home in Mosman Park on Friday morning.

A person who provided care services for the teenage boys, who are understood to have autism, alerted police about 8am.

Police found the bodies in different parts of the home, as well as a note, describing the deaths as a “devastating tragedy”.

Maiwenna Goasdowe, 49, and Jarrod Clune, 50.

Jarrod Clune, 50, was among the four found dead. Picture: Facebook

The West Australian reports the note contains words to the effect of “don’t enter” and “call police”.

Three pets — two dogs and a cat — were also found dead at the property.

Both teenagers had pre-existing medical conditions, but police did not explain further.

“We do know that both children experienced significant health challenges,” Detective Inspector Jessica Securo told reporters.

“The family had engaged with care services but I’ll leave it at that at this stage.”

WA Police are investigating a suspected double murder-suicide after four people — a 50-year-old man, a 49-year-old woman, and two teenage boys — were found dead in a home. Picture: Justin Benson-Cooper / The West Australian / POOL

The bodies were found on Friday morning. Picture: Facebook

Ms Goasdowe — who was known as Mai — was born in Morlaix, a small town in France with just over 15,000 residents.

She was part of several online support groups and described her sons as being at the higher end of the autism spectrum.

It is understood the boys attended Christ Church Grammar School, although it is not clear whether they were current students at the school.

Leon, 16, and Otis, 14. Picture: Facebook

It is understood the boys attended Christ Church Grammar School. Picture: Facebook

According to a school newsletter, at least one of the teenagers attended the school’s Peter Moyes Centre, which assists children with autism.

Mr Clune graduated from the school about 1991-92. It is understood he was a prefect and on the school surfing team.

The couple purchased their Mosman Park home for $1.4m in 2016. It was recently estimated to be worth more than $3m.

French-born Maiwenna Goasdowe, 49, had previously described her sons as disabled. Picture: Facebook

Three pets — two dogs and a cat — were also found dead at the property, police confirmed. Picture: ABC News

Inspector Securo said it was not yet known when the tragedy occurred.

“At this stage, I’m not able to disclose how these persons are deceased,” she said.

“However, I do reiterate that there doesn’t appear to be a violent incident that has occurred at the house.”

Police also confirmed the family had no prior reported domestic violence issues and no weapon was used.

A note was left at the scene, though authorities have not disclosed its contents. Picture: ABC News

“At this stage, there’s two parents and two children, so we will treat it as a double murder-suicide,” Inspector Securo said.

“There is no ongoing risk to the community.

“What I can advise is that there was no weapon used during this incident, and the family have no reported family violence matters with police.

“This tragic incident occurred only this morning and it will take time for investigate the full circumstances surrounding this incident.

“We urge members of the public to stay away from the area and be mindful that several streets in its vicinity are blocked.

“This is a highly distressing situation for all involved, from community members to the person that located the family to our first responders.”

Police say there were no signs of a violent incident and no weapon was used during the tragedy. Picture: Justin Benson-Cooper / The West Australian / POOL

Inspector Securo would not go into the content of the letter found at the property, but said it would form part of the police investigation.

“I can’t go into the details or the contents of the note, or who wrote it,” she said.

The investigation is ongoing, with homicide detectives examining the scene, reviewing CCTV, canvassing neighbours and conducting a full forensic assessment.

The two teenagers had significant health challenges, but police did not provide further details for privacy reasons. Picture: ABC News

Inspector Securo said officers who attended the scene were in shock.

“It’s not often that our officers come across such a tragic event with this many persons deceased,” she said.

“That’s why we employ our health and welfare teams, and our police chaplain, to attend the scene as soon as possible, speak to the officers, wrap our arms around them, and make sure they are OK.”

The surrounding area has been cordoned off, with police urging the public to stay clear.

Sandhya Sringar, who lives a few houses away from the home, described it as “immensely disheartening”.

“It’s really terrible to see such a young family and such young lives cut short — it’s immensely disheartening,” she told reporters.

“If it is a natural death, we can accept it, but if it is something like this — lives cut short — it’s terrible news.

“My sympathies go to those loved ones who are left behind, and I pray and hope that they get the strength to recover from where they are.”

Police have confirmed the family had no prior reports of domestic or family violence. Picture: Justin Benson-Cooper / The West Australian / POOL

Curtin MP Kate Chaney said the news was “shocking and devastating” for the community.

“My thoughts go out to the friends and relatives of this family, as well as the first responders, and the neighbours and local community who knew them,” Ms Chaney said.

“This heartbreaking loss of four lives will have lasting effects throughout our community.

“I hope the police investigation will provide more information soon about the circumstances that led to this tragic event.

“I encourage everyone impacted by this news to hug their loved ones.”

Police Minister Reece Whitby described the deaths as “devastating and tragic”.

“My thoughts are with the families, loved ones and communities affected,” Mr Whitby said.

“I thank WA Police, paramedics and all first responders for their actions in dealing with what are extremely confronting circumstances, and I also want to acknowledge the person who attended the home and alerted police.

“WA Police have commenced an investigation but have advised there are no safety concerns to the community.”