Police investigating the robbery of a south west Sydney service station earlier today have released CCTV footage of a person who may be able to assist with their inquiries.

Just before 5am (Friday 27 July 2012), a man entered the premises on New Canterbury Road, Hurlstone Park.

After selecting items in the store, the man approached a 22-year-old male shop attendant, produced a knife and demanded money and cigarettes.

The employee complied before the assailant fled in the direction of Garnett Street.

Detectives have released CCTV images of a person who they would like to speak to in relation to the matter.

The person depicted in the images is described as being a male of Caucasian appearance with fair complexion. He is about 25-35 years-old and 175cm tall, and of thin build.

At the time of the incident, he is shown wearing a black woollen beanie, black long-sleeved jacket and dark blue pants.