Luke Durbin was last seen leaving an Ipswich nightclub
The mother of a teenager reported missing after a night out in Suffolk four years ago is appealing again for information about his whereabouts.
Luke Durbin, 19, was last seen on CCTV in Ipswich on Friday 12 May 2006.
His mother Nikki Durbin reported him missing a day later when he failed to return to his Hollesley home.
Inquiries have not progressed in spite of searches, publicity and bank checks and now Mrs Durbin wants anyone with any new information to contact police.
Luke, who would now be 23, became separated from friends at a nightclub and was last seen on CCTV in Dogs Head Street going into Ipswich bus station at about 0400 BST.
In the appeal for more information police said his disappearance was out-of-character as he had never been out of touch with his mother for longer than 24 hours.
"He did not turn up for work and failed to pick up personal property - including his mobile phone - from a friend's house," a police spokesman said.
Police want to trace the driver of this vehicle seen in Ipswich
Detectives want to trace the occupants of a silver vehicle - possibly a Volvo or Mercedes - spotted on CCTV being driven past Tinkerbelle at Orwell Place.
The vehicle was heading from Tacket Street in the direction of the Spread Eagle public house at about 0409 BST on Friday 12 May 2006, police said.
To date, all enquiries and appeals have failed to produce an explanation for what happened to Luke.
Acting Det Insp Ian Addison said police continue to look for any new leads.
"The investigation remains open and every time we have issued an appeal over the past four years it has generated new enquiries.
"Unfortunately these have come to nothing.
"We have been aware from the start of rumours that he had met an untimely end but there is no evidence of this."
Luke is described as white, 5ft 10inches tall, of slim build, with short brown wavy hair and blue eyes.
At the time of his disappearance he was wearing a long-sleeved collared shirt, blue jeans and brown suede shoes.