Police were called to the petrol station on Penola Road just after 1.15am on Tuesday 8 November.

Upon speaking with staff, it was discovered that two men had entered the store and allegedly threatened the attendant with a hammer.  Police will allege the men then stole cash and cigarettes.

Fortunately, the staff member was not physically injured during the robbery.

Investigations by police led them to arrest a 25-year-old man from Mount Gambier. He has since been charged with aggravated robbery.

Investigations are continuing to identify the second suspect.

Detectives have released CCTV images of the second suspect.  He is described as aged in his mid 20s, about 178 cm tall, with a medium build and an olive or tanned complexion.  He has sleeve tattoos on both forearms.

Anyone who recognises the man pictured or has information that may assist the investigation is asked to contact Crime Stoppers on 1800 333 000 or online at http://crimestopperssa.com.au