The robbers suffocated the security officer to death when they sealed his mouth with a solution tape during the operation.
Police from the Atonsu divisional command arrived at the bank premises to pick the lifeless body of the security officer.
However, the police have launched an investigation into the robbery incident.
Several armed and dangerous criminals are loose in Ghana.
Bravery daylight armed robberies seem to be on the rise following reported cases of criminals on motorbikes attacking occupants of cars.