Detectives have released an artist's impression of a mystery man whose naked and badly injured body was found washed up on a beach in Cornwall.

Officers are also asking for information about a black and white photograph of a small boy found in a wallet close to where the man's body was found. They do not yet know if the picture, which has the date 13 April 1952 on the reverse, is connected to the man.

The body, clothed only in socks and one walking shoe, was found last Tuesday at Perranporth on the north Cornish coast by a member of the public.

Police said the man suffered multiple injuries and believe he had been in the sea for no more than 24 hours.

The man is described as white, aged 50-70, of thin build, 5ft 5in to 5ft 7in, with receding white hair and a thick white bushy beard.

Detective Chief Inspector Dave Thorne of Devon and Cornwall's major crime investigation team said: "We believe the artist's impression is a true likeness of the man we are trying to identify. As you can see from the image he has some distinctive features including a bushy white beard and white receding hair.

"It's been a week since his body was found on Perranporth beach and his identity is still a mystery. By releasing this image we are hoping that someone will recognise him and come forward with his name, allowing us to progress with the investigation and bring us a step closer to finding out what has happened to him. He is someone's brother, father, uncle or friend and someone somewhere will be missing him."

Police said that after a postmortem, the man's death is being treated as suspicious. Injuries were found on the body that are not consistent with drowning and cannot be easily explained. Officers have released a series of photographs of items found on or near the body. These include the brown walking shoe he wore. A black and white woolly hat and a rucksack were found on Perranporth beach on the same day as the body.

Thorne added: "Finding out the identity of this man is key to the investigation. Without knowing who he is, it is difficult to establish the circumstances surrounding his death.

"Perranporth is a small community that 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."