'Very tragic': Mother arrested after son fatally stabbed on NSW South Coast

Inspector Deborah O'Reilly could not confirm if there was a history of violence between the mother and son, or if the accused woman was under duress.

"It’s my understanding that there was a verbal altercation that led up to it [the stabbing]," Inspector O'Reilly said.

The inspector said the woman was "understandably very upset".

"Any incident like this is very tragic," Inspector O'Reilly said.

AAP reported that investigators were looking at the possibility Mr Russell's mother had armed herself following an argument.

Nine News reported the Mr Russell's father and his partner were also at the Sanctuary Point home at the time of the incident.

A police spokeswoman said detectives did not believe the mother and son lived at the Sanctuary Point home together.

Neighbours told Nine News they did not hear anything on Monday night, and were "shocked" to learn the news.

"It just doesn’t make sense, just shocked by it all really," Barry Baxter said.

"You hear about it on the news and yet here it is right here, next door."

Mr Russell's friends mourned his death on social media.

"God bless Daniel and I know you're in a better place now and I'll see you one day," one friend wrote on Facebook in the wake of the manslaughter charge.

Sanctuary Point mortgage broker Ellen Thornthwaite, who spent Tuesday morning meeting with other local business owners, said the community was "shocked" and "saddened" by the news.

"A lot of people are very shocked - I am myself," she told AAP.

"I'm sure there are many people who will be impacted by this, and having no idea what the circumstances are behind it - it's a tragedy regardless."

She said there were known issues with drugs in the area but something like this was totally unexpected.

With AAP