The man was wearing a distinctive blue hooded sweatshirt with large white lettering on the front and back. He wore dark coloured long pants with blue sports shoes.
"This offender has run into the bank and demanded cash while pointing a shotgun at staff and he needs to be held to account for what he's done, fortunately no one was hurt," Baldwin said.
"Blockhouse Bay is a tight knit community and we are appealing for the public to contact us if they saw anything unusual or out of the ordinary on Tuesday afternoon. The robbery occurred at 4.10pm on a weekday after schools had finished and there would have been a lot of people in the area at the time and urge anyone with information to call us."
Call police on (09) 302 6557 or anonymously call Crimestoppers on 0800 555 111 if you have information.