A South Coast man has been charged with terrorism offences a week after his brother was arrested over the alleged right-wing plot.

Benjamin Lucas is due to face Nowra Local Court on Saturday after being arrested outside a police station last Sunday.

On Friday night he was charged with one count of acts done in preparation for, or planning, terrorist acts and is facing life in prison.

He was also charged with two counts of possessing a prohibited firearm.

The Batemans Bay man allegedly had hunting knives and survival equipment in his car and was charged after a series of search warrants were carried out over the last five days.

The 23-year-old is the older brother of Sanctuary Point man Joshua Lucas, 21, who was charged with planning a terrorist act after police uncovered an alleged right-wing plot to attack an electrical substation on the South Coast.

Police will allege the brothers were involved in early planning for a terrorist act and were trying to obtain military equipment, including firearms, and other items capable of making improvised explosive devices.

During a search of his Catalina home, officers allegedly found extreme right-wing and anti-government material, as well as hunting knives, survival equipment and a replica firearm.

Police have also raided properties at Sanctuary Point, Falls Creek and Tapitallee on the South Coast over the past three days.

Authorities said the NSW Joint Counter Terrorism Team investigation was ongoing.

-AAP