The hunt for Michelle Bettles' killer is one of the biggest cases Norfolk police has handled, with 674 DNA profiles taken and more than 9,000 statements collected.
Over the years, officers have questioned three suspects, but when their alibis checked out they were released.
The original inquiry also identified the DNA of an individual, but that line of enquiry ended with the person eliminated as a suspect.
Michelle was the one of four women who had been Norwich prostitutes to vanish from the city streets in the space of a decade.
The other three were: Natalie Pearman, 16, who was found strangled to death and dumped in a lay-by at Ringland Hills outside Norwich in 1992; Kellie Pratt, 29, who disappeared from the red light district in 2000; and Hayley Curtis, 23, who was violently beaten and murdered in 2000.
Philip Stanley was convicted of Ms Curtis' murder in 2005 and is serving a life sentence, but the other cases remain unsolved.
Police examined possible connections to Suffolk serial killer Steve Wright, who had run the Ferry Boat pub in Norwich's red light district, but did not actively link him.
Much of the initial inquiries into Michelle’s murder involved tracing her movements in Norwich on the night of March 28 and cold case officers are still investigating new potential sightings following the fresh appeal for information earlier this year.
“There are several sightings of her, six in fact in and around Queen’s Road, City Road and Ber Street areas of Norwich, which was a red light district at the time,” said Andy Guy, major crime review manager.
“There are numerous sightings of her there. We believe she was working there up until around midnight of that evening.”
What happened to Michelle?
•Thursday, March 28, 2002
8.30pm: Michelle was captured on CCTV walking along St Benedict's street from her flat on Dereham Road.
9pm: She was meant to see a client in the city but never showed up
11.30pm: Michelle seen by fellow prostitute Tracy Kennett on City Road, Lakenham. There is another possible sighting of her on Carrow Hill after midnight.
• Easter Sunday, March 31
Michelle's body is found by a dog walker in woodland near Podmore Lane, Scarning, at 10.15am.
Police believed she was killed somewhere else and dumped on either Saturday night or Sunday morning.
A 4x4 is seen by people working on a house in Rushmeadow Road at 9.30pm on Saturday and heard with its 'engine racing'. The driver has never been traced.
A black leather jacket she was wearing has never been found.
• Police are asking anyone with information to contact the Major Crime Review Team on 01953 423819 or email unsolvedcasereviews@norfolk.police.uk
• Alternatively, you can access the public portal via the website (mipp.police.uk) or can contact Crimestoppers anonymously on 0800 555 111.
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