A 20-year investigation into the murder of backpacker Kirsty Jones has been closed.
Ms Jones, 23, died in Thailand where the 20-year statute of limitations on the case ended on Sunday.
No-one can now be prosecuted for the rape and strangulation of the young woman from Tredomen, near Brecon, Powys, at a guesthouse in August 2000.
Speaking ahead of the 20th anniversary, her mother Sue Jones said it was "a really sad time for us as a family".
"We have worked hard over all of these years to keep the Thai authorities interested in Kirsty's case and to ensure that the investigation continued to try to identify the persons responsible for her murder," she said.
She added that her "bright, intelligent, independent" daughter had the "world at her feet".
"Kirsty has gone from our lives, whilst her killer remains at large," she said.
"Had they been brought to justice the sadness and emptiness would remain the same but it may have brought us some closure.
"I hope we have done her proud in trying to get justice."
Ms Jones had visited Singapore and Malaysia before moving on to Chiang Mai, Thailand, in early August 2000.
She checked into a guest house and went trekking in the mountains, sightseeing and meeting people.
During the early hours of 10 August, after an evening with friends, Ms Jones was attacked and murdered in her room.
Det Supt Phillips, of Dyfed Powys Police, said: "No-one has ever been prosecuted for Kirsty's murder and the Thai Department of Specialist Investigations has now closed the case, meaning a permanent end to the investigation.
"Myself and colleagues before me have been in regular contact with Kirsty's family throughout, and we share their deep disappointment that no-one has ever been brought to justice."