Sentencing proceedings of Henri van Breda are expected to get underway in the Western Cape High Court on Tuesday.

On May 21, Judge Siraj Desai found Van Breda guilty of murdering his parents and brother at their family home in Stellenbosch in 2015.

He was also convicted of the attempted murder of his sister and of defeating the ends of justice.

Van Breda had claimed a masked intruder attacked his family with an axe but Desai dismissed this, saying it was unlikely an outside intruder committed the crimes.

The National Prosecuting Authority has said it expects Van Breda will be handed a life sentence.