Luke Durbin missing inquiry: Seventh anniversary appeal
More than 100 people have now been interviewed by police investigating the disappearance of a Suffolk teenager seven years ago.
Luke Durbin, of Hollesley, was 19 years old when he failed to return home after a night out in Ipswich in May 2006.
Two men, arrested last year for being "concerned in the murder" of Luke, were released without charge in March.
Suffolk Police hope fresh appeals on the anniversary of the disappearance will bring new information.
Officers said they had a clear idea of Mr Durbin's movements after he left Zest nightclub up until his last confirmed sighting on Dog's Head Street in Ipswich at 04:00 BST on 12 May 2006.
Police said CCTV images of him at the railway station, a taxi rank and crossing the road towards the cattle market bus station suggest he was trying to get home.Potential visits
A witness also reported seeing Mr Durbin in a dark blue Renault Megane near the Turban Centre, Woodbridge, between 11:00 and 14:00 BST on 13 May.
Det Supt John Brocklebank said: "You don't just disappear off the streets at four in the morning, so he's potentially visited somebody in Ipswich or en route back to Hollesley.
"If Luke came round, called on you, or the partner of anybody, we ask them to come forward and we'll treat that information sensitively and discretely.
"The investigation does move forward piece by piece and every time we make an appeal, we get some new piece of information."
Mr Brocklebank said they were treating it as an 'unlawful killing' inquiry.
But he said the discovery of three women in Cleveland, Ohio, in the US this week after they had been missing for 10 years showed they had to keep an open mind.
"I don't want to build up hope or expectation that that is going to happen here, but you never know," he said.