Armed Crime Squad detectives have released images of two men they wish to speak to following a robbery outside a bank in Broadmeadows in May.
Investigators have been told the man carrying a back pack attended a shopping centre on Pascoe Vale Road about 4.30pm on Monday 2 May.
It is believed the offender approached the victim outside the shopping centre, making demands to hand over the bag.
He then produced a firearm and the victim handed over the bag containing a substantial amount of money.
The offender fled the scene, returning to a late model silver Mercedes.
The car was later found burnt out in an industrial area on Clifford Road in Somerton about 8pm that night.
It is believed a grey 2009 Lexus sedan, registration 1GZ 1BJ was in the same Somerton area about 8pm, around the time the Mercedes was burnt out.
Detectives have released facial composite images of two men that may be able to assist with their enquiries.

The men are believed to have been in Munro Street, in the vicinity of Sydney Road in Coburg, about 4pm, which was approximately 30 minutes prior to the robbery.
Frankston Embona Armed Robbery Taskforce detectives are appealing for public assistance following an armed robbery at a Supermarket in Carrum Downs on Sunday.
It is believed an unknown man attended a store on Frankston – Dandenong Road about 7.10pm.
He threatened the attendant with a knife.
The man made demands for cash before fleeing the scene on foot.
No one was injured during the incident.
Police have released an image of a man they believe may be able to assist them with their enquiries.

Moreland Crime Investigation Unit detectives have charged two men following an alleged armed robbery of a Coburg jewellery store yesterday.
It’s alleged three men entered the Sydney Road store and stole jewellery from display cases about 6pm.
Two of the trio were detained by passers-by as they tried to leave the store.
Investigators have charged an 18-year-old Cairnlea man and a 19-year-old Derrimut man with armed robbery, aggravated burglary and theft.
The teenagers have been remanded to appear at Melbourne Magistrates’ Court in the morning.
Detectives continued to search for the third man.
Southern Metropolitan Regional Crime Team investigators as part of Operation Cosmas have arrested and charged two people today following a series of incidents across Melbourne’s south eastern suburbs.
Police arrested a 19-year-old Moe man and a 17-year-old Dandenong boy following a short foot pursuit through bushland near Dandenong Creek in Dandenong shortly after 9.15am.
The pair have been charged with armed robbery, theft of motor car, theft, criminal damage by fire, conduct endangering life and possess proceeds of crime.
The charges relate to a number of incidents including:
• An alleged armed robbery at a bottle shop on Springvale Road, Springvale about 11pm on 2 July;
• An alleged armed robbery where a vehicle was stolen on David Street, Dandenong about 10.45pm on 4 July;
• An alleged armed robbery at a service station on Heatherton Road, Springvale about 11.45pm on 4 July;
• An alleged pursuit on Chandler Road, Noble Park about 11.55pm on 4 July; and
• A car fire near Dandenong Creek, Dandenong Street in Dandenong about 9.15am today.
The 19-year old is likely to face the Melbourne Magistrates’ Court tomorrow.
The 17-year-old has been remanded to face a Children’s Court at a later date.
Darebin Crime Investigation Unit detectives are appealing for information after three masked men smashed their way into a Reservoir jewellery store yesterday.
Police have been told the men gained entry to the Broadway business by kicking open a locked door about 3.10pm.
Once inside, one man has threatened a male employee with a firearm, whilst another has smashed a jewellery cabinet with a wheel nut brace.
The men have gained access to display cabinets and a safe and placed a large amount of cash and jewellery into a black sports bag before fleeing.
Nobody was injured as a result of the robbery.
Detectives have released CCTV footage and images of the men in the hope it will assist the investigation.
All three men have been described as tall with thin builds.
The first man was wearing a black jumper, black pants and shoes, and had his head covered in a white material wrapping.
The second man was wearing a black hooded top with Adidas written across the back, black pants and shoes, a red face mask, and red gloves.
The third man was wearing a black hooded top, black pants and shoes, and a white face covering.
Frankston Embona detectives have arrested a 46-year-old man over an attempted armed robbery which occurred in Frankston last week.
Police have been told a man entered a service station on Nepean Highway armed with a knife about 5pm on Wednesday 22 June.
The man approached the attendant where he produced a knife and made demands for cash and cigarettes.
The staff member was able to flee to a back room and lock the door.
Police believe the man cut his hand when he stabbed the knife into a door, before leaving the scene empty handed. The staff member was not injured in the incident.
The Frankston man was arrested and interviewed last night.
He has been charged with attempted armed robbery and common law assault.
He has been bailed to appear at the Melbourne Magistrates’ Court on Monday.
Police are appealing for public assistance following two armed robberies and an assault that occurred in Melbourne’s inner east earlier this month.
Investigators have been told a woman was threatened by a man with a firearm as she left a business on Erin Street, Richmond, about 8.50pm on June 13.
The man demanded the woman hand over her purse. The woman refused and the man left empty handed.
At about 10.20pm, it is believed a man was approached by the the same man in Yarra Park, who again produced a firearm and demanded money.
In this instance the victim handed over a small amount of cash and the men fled.
Police believe the same man was also involved in an assault at a carwash in Hoddle Street earlier in the evening.
Investigators have been told a male victim was assaulted by a man whilst waiting to buy a kebab. The victim received minor injuries to his head as a result of the assault.
Investigators have released CCTV images and a facial composite of a man they believe may be able to assist them with their enquiries.

The man is perceived to be of Caucasian appearance, bald, and was unshaven.
At the time of the incident he was wearing a black hoodie, and light coloured pants.
Police are appealing for public assistance following an armed robbery in Lalor last month.
It is believed the victim, a taxi driver, picked up an unknown man on Flinders Street, Melbourne on Friday 20 May about 12.30am and was asked to drive to the intersection of Edgars and Franklin road, Lalor.
When they arrived at the destination the man pulled out a firearm and demanded money from the victim.
He then pulled money from the victim’s top pocket before searching through a bag on the floor of the taxi.
The man then fled on foot, travelling west along Franklin Road.
No one was physically injured during the incident.
Detectives from the Whittlesea Crime Investigation Unit have released images of a man they believe may be able to assist them with their enquiries.

The man has a distinctive tattoo on his left hand.
Armed Crime Squad detectives have charged two men following an armed robbery at a bottle shop and attempted murder in Kingsville in 2011.
The armed robbery occurred at a bottle shop on Geelong Road where a staff member was allegedly threatened before a shot was fired into the cash register in an attempt to steal cash on Saturday 1 October.
A shot was also allegedly fired at a driver in a nearby stationary vehicle who received a gunshot wound to the hand.
A 27-yearold Dingley Village man and a 25-year-old Hampton Park man have been charged with attempted murder, armed robbery and firearm related offences.
They have been remanded in custody and will appear at the Melbourne Magistrates’ Court tomorrow.
Police are appealing for public assistance following an armed robbery in Williams Landing last week.
It is believed an unknown man attended a store on Sayers Road last Thursday about 1.40am.
He selected a number of items before going to the counter and producing a firearm.
The man made demands for cash before fleeing the scene on foot and heading east on Sayers Road.
No one was injured during the incident.
Police have released images of a man they believe may be able to assist them with their enquiries.

The man is perceived to be of African appearance and was unshaven.
At the time of the incident he was wearing a black jacket, white pants and a black beanie.