U.K. mom has new hope of finding out what happened to her son — 30 years after he disappeared in B.C.

There's not a day that goes by without the thought of her missing son weighing heavily on the heart of Denise Horvath-Allan.

"As the years pass by, it gets worse," Horvath-Allan told CBC News. "You're totally immersed in the hope you will find the answers."

A search for answers that spans three decades, ever since her son, Charles Horvath-Allan, was last seen in Kelowna in 1989.

After countless trips to Canada and sleepless nights poring over documents related to her son's disappearance, Horvath-Allan's hope has been renewed — the cold case has been picked up by an international missing persons agency.

"I've been on this long road, alone," she said. "It's amazing, because I've been asking for help for so many years."

The disappearance of Charles Horvath-Allan

Charles Horvath-Allan was born in Ontario and raised in the U.K. His mother got married in B.C. and she and her husband honeymooned in the Okanagan.

Before his 21st birthday, Charles decided to travel across Canada, from Quebec to B.C.

His mother remembers the horror that struck her when she realized her son might never return, after he stopped calling her. 

"I was frantic, because I couldn't understand why he didn't telephone," she said. "I was anxious at the very beginning."

A year into the silence, Denise Horvath-Allan made the trek to B.C. to press for answers.

She discovered that local police had found some of Charles's clothing at a campsite. They asked her to identify the items, she said, telling her they believed her son was dead but didn't know how he died or why.

At one point, Horvath-Allan received an anonymous tip that her son's body had been dumped into Okanagan Lake. Days later, a team of divers found human remains in the lake, and police announced Charles's body had been found.

Lab tests later determined that the remains weren't his. To date, his body hasn't been found.

Hope renewed

Denise Horvath-Allan, now 71, has made more than a dozen trips to B.C. in search of her son, who is presumed dead. With her hope subsiding, she reached out to a group called Locate International — an agency dedicated to helping families of unsolved missing person cases.

The group agreed to take on the case of Charles Horvath-Allan. She got the news the same day she applied for a presumption of death certificate for her son.

"It's uplifting. It's such a relief that someone is going to help ... and hopefully in my lifetime resolve the case, and perhaps enable me to bring my boy home."

Locate International has partnered with several universities in the U.K. The team will go over documents related to the case. Horvath-Allan says one of the group's co-founder will also visit Kelowna once travel is safe.

In the meantime, she's pleading with anyone who might have information about her son to come forward. She hopes to bury him in Cambridge, England, next to her mother.

"Just please, help me find the answers to my son's fate."