Arlene Arkinson investigation detectives in blood appeal
Detectives investigating the murder of teenager Arlene Arkinson have appealed for two women whose blood was found in a flat they searched to contact them.
Fifteen-year-old Arlene, from Castlederg, County Tyrone, went missing in August 1994 after a night out at a disco in Bundoran, County Donegal.
In 2012, a derelict flat at Main Street in Castlederg was searched after new information became available.
Specimens of blood belonging to two women were found during the search.
The officer now leading the investigation, Detective Superintendent Karen Baxter, said: "These blood specimens belong to two different women.
"Tests have confirmed they are not from Arlene. But neither specimen has registered on the national DNA database.
"On the 20th anniversary of Arlene's disappearance, I would ask that any woman who was in this flat, at 49a Main Street which has since been demolished, at any time to make contact with police.
"They have a story to tell and we want to hear it. Twenty years on, they just need to get over the fear, get over what their concerns are and please come forward and speak to us."
A number of searches for Arlene's body have been carried out at various locations, but she has never been found
In 2005, convicted child killer Robert Howard was acquitted of the teenager's murder. The jury was unaware he had a history of sex attacks and that two years earlier he had been found guilty of murdering Hannah Williams, 14, in south London.
Officers will be conducting a number of land searches in various parts of Tyrone and other locations over the coming months.
The searches will be carried out by a small team assisted by dog handlers and body recovery dogs.
"This investigation will continue. It will be progressed as far as we can take it," Det Supt Baxter said.
"Indeed, I can confirm that our enquiries have involved detectives interviewing a man in England."