An Australian man and two children have been found dead in Bali in what local police are treating as a possible murder-suicide.

The trio were reportedly found at a bungalow in Kuta, a resort town on the Indonesian island's southwest coast, on Sunday morning.

They have been identified in multiple media reports as Western Australian man Damien John Shaw, 56, his six-year-old daughter and four-year-old son.

WA Premier Roger Cook said the incident was horrific, stressing investigations were ongoing.

"This is a very sad, sad situation and our hearts go out to everyone involved," he told reporters on Monday.

"We hope that we can get to the bottom of what's gone on here as soon as possible."

The Department of Foreign Affairs and Trade said it was providing assistance to the family.

"We send our deepest condolences to the family at this difficult time," a DFAT spokesperson told AAP.

"Owing to our privacy obligations we are unable to provide further comment."