The body of a male was found on Saturday morning on the sandy beach of Canide Sul, in Canidelo, Vila Nova de Gaia, the Porto District Rescue Operations Command (CDOS) confirmed to Notícias ao Minuto.
The alert was given at around 9.13am by a surfer who was on the beach.
The body was in an advanced state of decomposition, which is why it was not possible to identify the victim.
The Coimbrões Volunteer Fire Brigade told Notícias ao Minuto that it was a male.
The body was later sent to the Institute of Forensic Medicine to be examined.
Jornal de Notícias also says that there is a possibility that it is the 16-year-old who went missing a week ago at sea.
At the scene were members of the Coimbrões Volunteer Fire Brigade, the Maritime Police and the National Institute for Medical Emergency (INEM).