A man is receiving treatment at a Christchurch psychiatric hospital after an incident involving the Armed Offenders Squad on Tuesday afternoon.
Police say that at about 3pm, a man told a doctor at a medical practice in Riccarton Road that he had a hand gun.
The man, 54, gave himself up after cordons were set up around the area and the building evacuated.
Detective Sergeant John Rae says the gun was found to be an air pistol. He says the man is unlikely to be charged.