The owner has been locked up at the Waigani Police Station cell.
He is also the first to be arrested by NCD police following unceasing investigations into the robbery.
CID Police say the six suspects involved in robbery are known but are yet to be captured by police.
Three other guns alleged to be used in the robbery as well have also been confiscated by police and owners of these firearms have been called in to be questioned by police.
Police are looking to get answers from the owners and tracking down the wanted suspects.