The Ministry of Justice says a formal investigation is underway after security staff at the Christchurch District Court failed to notice a lawyer had taken a gun into the building.
Lawyer Craig Ruane says he accidentally took the air pistol to the Christchurch District Court in his briefcase about three weeks ago, but it wasn't noticed until he went to leave and he is very embarrassed by the incident.
The ministry said on Wednesday that court security is taken very seriously and would make no further comment until the inquiry had been completed.
Security expert Sir Kenneth Stevens, executive chairman of Glidepath, which installs airport security systems, said he would be very surprised if the equipment wasn't set up correctly.
The Law Society believed current security measures are adequate, but said it was confident any lessons would be learned.