Bomb experts were called to Woden police station after a man entered the front office with what appeared to be a pipe bomb, on Thursday afternoon.
The streets outside the police station were blocked to traffic and the front office of the station was locked down to the public for about one hour while two members of the bomb response team investigated.
The bomb team cleared the item from the office and gave the all clear at 2:25pm, a police spokeswoman said.
The station continued to operate as usual and was not evacuated during the incident.
The man dug up the pipe while gardening in his backyard and took it to the station at about 1:30pm as he thought it was a bomb.
The police spokeswoman reminded the public to leave suspicious items where they found them so as not to put themselves or others at risk.
"While he acted with the best of intentions, by handling and transporting the item he potentially placed himself and other members of the community in danger," the ACT Policing Facebook page said.
"Old ordnance are often unstable and can detonate easily, so we would encourage people to contact police immediately on 131 444 if they discover such devices or suspicious items."