A person is in a critical condition following a non-fatal drowning at Cornwallis Wharf in West Auckland.

Emergency services were called to the incident on the Manukau Harbour at 6pm after receiving reports a man had been pulled from the water unresponsive.

A St John spokesperson said a patient had received CPR for a while on scene, and was being transported to Auckland City Hospital by the Westpac Rescue Helicopter.

Police are at the scene speaking with witnesses.