Campaspe Crime Investigation Unit detectives are investigating an attempted armed robbery in Echuca last month.
Police said it was understood a male brandishing a knife entered a petrol station on Ogilvie Ave, Echuca, about 5.45am on May 23.
Investigators have been told the male threatened a shop attendant and demanded money, before fleeing the scene empty-handed, police said.
No-one was physically injured.
Investigators have released CCTV and images of a male they believe may be able to assist with their investigation.
He is perceived to be Caucasian in appearance, aged in his mid to late teens, of medium build and approximately 160cm tall.
The male was seen wearing a grey and black speckled hooded jumper, black tracksuit pants and black shoes.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au