Steven Clark vanished from Marske-by-the-Sea in Saltburn on December 28, 1992, and is presumed to have been murdered despite police having never found a body.
The case was re-opened as part of a cold case review this year, and since then Mr Clark’s elderly parents, Doris and Charles, have been arrested and questioned about his death while their neat semi-detached home was searched in September.
Both have been released under investigation and deny any responsibility over their son's disappearance, with his mother describing the situation as “absolutely ludicrous”.
Cleveland and North Yorkshire Cold Case Unit has now released new footage of Mr Clark, who was 23 when he was last seen going into a gentlemen's public toilet on Saltburn promenade.
His mother had gone into the ladies at the same time. He was not seen coming out of the toilets and did not return home.
The short clip was taken from a training video for the Redcar branch of the Rathbone Society charity - for which Mr Clark worked - in the 1990s.
It is hoped the footage may be able to refresh people's memories in the hopes of volunteering new information which could assist detectives.
It has been previously shown as part of two public television appeals into Steven’s case, one which was filmed in 1993 for London Weekend Television. There was also an appeal in the same year shown on Carlton Television.
Detective Chief Inspector Shaun Page said: “Steven had a distinctive walk as a result of a childhood road accident, and the footage shows his walk, and you also hear his voice when he is sat at a computer and speaking.
“These clips were made public not long after he went missing, but we are releasing it as part of the new investigation in the hope that people who see it and come forward, if they haven’t spoken to us already.
“This year, the bank holiday falls in exactly the same way as it did the year that Steven went missing and many beach-goers will walk around Saltburn as they did then."
In September, a witness came forward providing what police said was "significant" new information in Mr Clark's case, while earlier this month, detectives uncovered the identity of a person who sent them a mysterious letter in 1999 claiming to know who the killer was.
Det Chief Insp Page added: "The response from the public so far has been fantastic, but I would urge others to come forward.
“Crimestoppers is offering a £10,000 reward in this case, and you can give information to them entirely anonymously.”
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