Emergency services were called at around 11:45am on Saturday 24 June following reports of a child having fallen from the harbour wall in Padstow.
The child, who is a 5-year-old local boy, was taken to Treliske by Air Ambulance and later transferred to Bristol Hospital for treatment.
He sadly passed away whilst in hospital with his parents present.
Currently, police are treating this death as a tragic accident.
Police continue to undertake enquiries on behalf of the coroner.
Anyone with further information can contact the police quoting log number 435 24 June.
Our thoughts are with family and loved ones of the child during this difficult time.