Scott Fletcher was last seen near to the Jet garage on the A181 at Wheatley Hill in Durham on the evening of 11 May, 2011.
Seven people remain on bail after being arrested on suspicion of his murder.
Cleveland Police said:  "Scott's family are still struggling to come to terms with what's happened."
Det Supt Jon Green added: ""We want to be able to end this nightmare for them and provide some answers.
"I believe we are making progress and would again ask anyone with information which could help to contact Cleveland Police."
The investigation into a Hartlepool man's disappearance is continuing on the fifth anniversary of his last sighting, police have said.