Police are appealing for a witness in Truro who may have seen Alan Jeal on the day before his body was found to come forward.
The man detectives would like to speak to was in The Leats area of Truro at around 6.30pm on Monday, February 24.
He was wearing shorts and a waterproof jacket.
DCI Dave Thorne, Senior Investigating Officer, said: “We would like to speak to this man in case he saw or spoke to Alan.”
Alan’s body was discovered on Perranporth Beach by a member of the public while out walking his dog at around 2pm on Tuesday 25 February. He was naked apart from wearing socks and one walking shoe.
Alan, 64, from Wadebridge, lived alone and was not reported missing to the police.
Multiple injuries were found on his body which are inconsistent with drowning and cannot be easily explained.
Officers have previously released CCTV footage in the hope of tracing three people stood at a bus stop in Truro with a man matching Alan Jeal’s description.
The footage shows the man believed to be Alan talking to someone at the bus stop at 6.45pm on Monday 24 February at the Lemon Quay bus station.
Two other people were also waiting for the bus, destined for Perranporth, at the same time.
The man believed to be Alan is wearing a blue jacket and a rucksack, with a bald head on top and beard.
DCI Thorne added: “We are keen to speak to these three individuals, particularly the man who was talking to the man believed to be Alan, as they may hold vital information about where he went next.
“It is not clear from the footage whether Alan got on the bus or walked away.
Police are using CCTV to trace his last movements on Monday 24 February, the day before his body was found.
Detectives have also released a map of the town and a series of CCTV clips and images showing a man, believed to be Alan, in Truro city centre that evening.
It is believed that Alan got the number 594 bus from Wadebridge to the Lemon Quay area of Truro, arriving at the bus station at 6.14pm. He was seen walking towards the public toilets at The Leats, and then seen at 6.36pm in Boscawen Street.
Police have revealed that when Alan’s body was discovered, a sock was found in his mouth.
“We can’t think of an explanation as to why it would be there and this is one of the reasons we are treating Alan’s death as suspicious.
“Officers are keeping an open mind as to the cause of his death. Murder is one possibility we are considering, however his death may have been caused by accident or suicide.
“We would also to hear from anyone who may have witnessed the discovery of his body on the beach on Tuesday 25 February and may have recorded the incident on their camera or mobile phone,” added DCI Thorne.
Police have also released a series of photographs of items which were found on the beach.
The Regatta jacket, wallet and photograph, which were found on Wednesday 26 February are believed to be Alan's.
It is believed that the photograph found in the wallet shows Alan when he was two years old in the family home.
The rucksack with green webbing, found nearby on the same day that the body was found, is believed to be Alan's but it is not yet known if the woolly hat was his.
All of the images can be viewed on flickr: http://www.flickr.com/photos/devon-cornwall-police/sets/72157641792574233/ and CCTV footage can be found on the DC Police YouTube channel: https://www.youtube.com/playlist?list=PLB8D8F1957A146B7A.
Ayone who saw Alan on the days before his death or has any information that could assist with the investigation, is asked to call 101 quoting log 381 of 1 March, or alternatively call Crimestoppers anonymously on 0800 555 111.