Officers were called around 8.20pm following reports of concern for two people in the water
One man sustained minor injuries and received treatment at the scene.
A second man was recovered and given emergency medical treatment by Ambulance and Coastguard teams - but the man from Oxfordshire, was confirmed deceased at the scene.
A Force spokesperson said: "His next of kin have been informed. The death is not being treated as suspicious and a file will be prepared for the coroner."
A spokesperson for the South Western Ambulance Service NHS Foundation Trust (SWASFT) said: “We were called at 20.17hrs on Tuesday 29 July to an incident in Mawgan Porth. We sent three double-crewed land ambulances, a rapid response vehicle, a first responder and an air ambulance to the scene.”
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