"He was a similar looking male to the person who robbed the service station - he was hanging around the Carlyle St area and he clearly raised suspicions."
Mr McGregor said other people apart from those who called police would have seen the man and he wanted to hear from them.
It was not known if he had access to a vehicle, although Mr McGregor said sightings of a car parked in or leaving the Edmundsen St area of Onekawa before and after the robbery may provide further clues for police.
"It is very likely a car was used," he said.
The robbery happened about 7.15pm and the lone robber, who appeared to have been concealing a weapon of some sort under his jacket, had run off through an alleyway into Edmundsen St.
The station attendant, who was left shaken but unharmed, told a customer who arrived just seconds later what had happened and that the offender had made off through the alleyway.
The man went looking but there was no sign of anyone.
Mr McGregor said police want to hear from anyone who may have seen a car parked in or leaving the immediate area around the time of the robbery.
The offender is described as in his late 20s or early 30s, about 1.69cm (5ft 7in) tall and of solid build.
He was wearing a black jacket with a white band around the wrists and bottom of the jacket, black pants and a black balaclava. He appeared to also be wearing a blue or red jersey or hoodie under his jackets and white shoes.
Anyone with any information about the robbery or who may have seen anyone acting suspiciously in the area is asked to contact Mr McGregor at Hawke's Bay police on (06) 211 3809 or anonymously through Crimestoppers 0800 555 111.
The Mobil Mart was the second Mobil station in the region to be targeted within a two-week period.
The Mobil Windsor station in Hastings was the target of an attempted robbery by a knife-wielding man on July 29, and police believe the distinctive green hoodie he was wearing may provide the clue they need.
They are appealing for the public's help in identifying the solidly built man who confronted the attendant about 8.30pm and demanded cash.
He fled after the attendant refused.
The man left on foot but a police dog was unsuccessful in following the scent.
"It is difficult to tell if he got into a car or hopped on a bicycle," Constable Steve Leonard said.
Mr Leonard said the would-be thief had covered himself unusually well, masking his face and wearing gloves.
Anyone who remembers seeing suspicious activity on the Tuesday evening near the Heretaunga St West service station, on the corner of Heretaunga St East and Madison St in Parkvale, is asked to contact Detective Sergeant Jason Crowe on (06) 831 0700 or phone Crimestoppers on 0800 555 111.
Mr Crowe said the attendant's actions were brave but he advised victims of such crimes to comply.
