A man has been found dead in the water after he fell overboard off the Dunedin coast.

Emergency services responded to a mayday call from fishing vessel FV Venture about a man overboard, with a rescue helicopter and local Coastguard heading to the scene about 1.30pm.

Police say the man was pulled from the water and medical attention was provided, however he sadly died at the scene.

The death will be referred to the Coroner.