Police were called shortly after 9.40am on Wednesday November 30 with reports a car had gone into the river at King Edward Quay, Colchester.
Officers assisted the fire service and coastguards to carry out a search and recover the Ford Focus, which was partially submerged and could not be reached until low tide.
Sadly the body of a 52-year-old man from the Maldon area was found inside the car, which was recovered from the water by crane.
Officers from the Serious Collision Investigation Unit will carry out an investigation into how the car came to enter the water.
However his death is not believed to be suspicious and a report will be prepared for HM Coroner.
Essex Police are not looking for any other person or vehicle in connection with this incident.