Cleveland Police are continuing to appeal into the murder of Vicky Glass, who was found dead in Danby 19 years ago.
Vicky was 21 when she disappeared from Middlesbrough town centre in 2000, and would have turned 40 last Saturday (Sept 21).
Her body was found in Danby in North Yorkshire in November 2000.
Cleveland Police announced in 2018 that the Historic Investigation Unit would reinvestigate the case after being given additional funding by the Home Office.
Detectives have continued to appeal to the public for information over a number of years in the hope that those with a guilty conscience come forward.
Inspector Pete Carr said: “Vicky would have been forty last weekend, but her life was cut short at such a young age and her family and friends have been robbed of precious time with her.
“Someone knows what happened to Vicky, and that information will have been a weight to carry over the last two decades.
"Now is the time to come forward, our investigation is continuing and someone may be able to give us the last piece of the jigsaw so we solve this case and get justice for Vicky and her family.”
Anyone with information is asked to call Cleveland Police on the non-emergency number 101 or Crimestoppers anonymously on 0800 555 111.
There is also a phone line (plus answerphone) into the inquiry team, this number is 01642 301499.