The nephew of murdered German backpacker Inga Maria Hauser has said his family will only be free of the “curse” of his aunt’s death once her killer is caught.
It comes after two men from Co Antrim were questioned by police this week in connection with the 18-year-old’s murder.
The Munich teenager’s body was found dumped in a remote part of Ballypatrick Forest, near Ballycastle, two weeks after she was last seen alive on a ferry from Scotland in April 1988.
The crime remains one of the Province’s most high-profile unsolved murders.
Two men, aged 61 and 58, were arrested in the Loughguile area on Monday and later released pending further inquiries.
In an emotional appeal on BBC Spotlight, friends and family of the murdered 18-year-old said they have not given up hope that her killer will be brought to justice.
Inga’s nephew Viktor Leibl said he is still hoping for a breakthrough in the investigation.
Mr Leibl, who was born after his aunt’s murder, told of the “extreme” impact her death had on his family, particularly his grandparents.
Inga’s father Josef died in 2006, while her mother Almut has dementia and lives in a care home in Austria.
Mr Leibl added: “The marriage of my grandparents suffered. They never divorced but they were never the same.”
He said his grandmother’s dementia was a “two-sided sword”, adding: “It’s a horrifying disease she has but she has none of the pain and the memory of her lost child, which might be a good thing.”
And he also revealed that his mother, Frederika, “feels guilty” as the last time she spoke to her sister before her death they had an argument.
“(Catching the killer) would be especially important for my mother. I hope if the murderer gets caught my mother can finally leave this behind and we can be free of this curse,” he added.
Inga’s friend, Walter Schreiner, urged anyone who knows who may have been behind the murder to help “close the case and give Inga back to us”.
He added: “We have to find the perpetrators. Thirty years is a very long time, too long.”
Paying tribute to his friend, Mr Schreiner said: “Everyone who knew her loved her. She was always smiling and shining. She was very intelligent and wanted to explore the world.”
The Spotlight programme also explored the mystery of why Inga, who had planned to travel from Larne to Belfast once she got off the ferry from Stranraer, ended up heading north instead.
In her final diary entry before she disappeared, the teenager wondered where she would be staying that night and said she needed “more money”.