The "mystery" death of an unknown man whose naked body was washed up on a beach is being treated as suspicious by police.
The unidentified man's body was found at high tide at 2pm on Tuesday at Perranporth beach in Cornwall.
Devon and Cornwall Police said the man's death is now being treated as suspicious following the results of a forensic post-mortem examination.
Multiple injuries were found on the body which are inconsistent with drowning and cannot be easily explained.
Police believe the man was in the water for no more than 24 hours.
The man was only wearing socks and one walking shoe when his body was found.
Police said a picture of a young boy was found in a black wallet in the pocket of a dark navy-blue Regatta jacket on the beach on Wednesday, and it may or may not have belonged to the deceased.
There was a date on the back of the photograph of 13 April 1952. Police said it is unclear what this date refers to.
It could be a date of birth or the date the photograph was taken.
Police described the man as white, aged 50-70 years old, of thin build, 5ft 5in - 5ft 7in tall, with white receding hair which was bald on top, and said he had a thick white bushy beard.
As well as a jacket, photograph and shoe found nearby, detectives are trying to trace the owner of a set of keys, consisting of a Citroen car key, two mortice lock keys, a hippopotamus keyring and a red fob.
It is not known whether the keys are linked to the man. If they are not, officers would like to eliminate them from their inquiries.
Detective Chief Inspector Dave Thorne, of Cornwall Major Crime Investigation Team, said: "Finding out the identity of this man is key to the investigation. Without knowing who he is, it is very difficult to find out what happened to him and establish the circumstances surrounding his death.
"Perranporth is a small community which attracts a variety of people and we are hoping someone will have seen something that could unlock this mystery.
"If anyone knows who he is from the details given, or has seen someone on Perranporth beach on Monday or Tuesday last week matching his description, we'd like to hear from you.
"We also urge anyone with any information relating to the items found on the beach, however insignificant it may seem, to get in touch."
Anyone with information that could assist with the investigation is asked to call police on 101, quoting log 381 of March 1, 2014, or the independent charity Crimestoppers, anonymously, on 0800 555 111.