The parents of two boys who were found dead at a home in the NSW central west have shared a heartbreaking tribute, saying the siblings “adored” each other.

Max Johnson, 7, and his brother Sam, 6, were found dead in Coonabarabran, north of Dubbo, about 2pm on Monday.

The boy’s 66-year-old grandmother, Kathy Heggs, was arrested in connection to their deaths and remains in a mental health facility.

Parents Samantha Heggs and Troy Johnson told 9News of their grief.

“They were just that close, they adored each other,” Johnson said.

The children were removed from their parents’ care by the Department of Communities and Justice four years ago.

“Max was never sick, he was always happy and healthy, he was the happiest,” Johnson said.

Sam battled cancer at just six months old and beat it.

His father described him as “the toughest little kid I have ever met”.

“What he went through, the pain, the way he beat that cancer. He’s my hero,” he said.

Police informed the parents of the boys’ deaths on Monday evening.

The next day, the parents say they discovered through media reports that Samantha’s mother had been arrested.

Kathy Heggs remains in a mental health facility in Orange.

Police say she is likely to be charged after an autopsy report is completed.

A small vigil was held tonight outside the boys’ home near Coonabarabran.