Yet Paul sees him regularly in his dreams; a place where his beloved older brother is still well and truly alive.

The question of how and why Gerhard Bruno Wagner disappeared has haunted his family since January 7, 1999. It made no sense that the well-liked 61-year-old would simply vanish. He was generous and was planning the next chapter of his life, which involved downsizing to an Ashgrove unit and sailing the 42-foot yacht he spent years building.

"I dream about him still," Paul told Fairfax Media. "They're silly dreams that he's still alive. I say to him: 'Where the bloody hell have you been?' I can't explain it, but that's what I do and that's why I won't give in."

On Wednesday morning came the breakthrough, a moment Paul and his brother Peter had been waiting years for. They were summoned to Brisbane's Roma Street police headquarters because of a major development in the case.

Robert Wagner - who is Paul, Peter and Gerhard's nephew - had been arrested over the murder.

For Paul, it was a landmark moment that triggered a range of emotions. There was relief, shock, sadness and then the "extremely difficult" scenario that one of the family's own could be responsible.

"Nobody wants that in the family," Paul said.

"Our family feel it is the start of recovery. Will we ever get over it? No. It'll stay with us for the rest of our lives because in the end it's not us getting closure so much. We're upset for my brother, for the life that has been lost."

Robert Wagner denies the charges and will be applying for bail soon, his lawyer says.

Despite Wednesday's dramatic events, many questions still remain.

The possible motive for the killing is yet to be revealed by prosecutors in court.

The Kawasaki Virago 750 motorcycle, ridden by Gerhard on the last day he was seen alive, has not been recovered.

Most importantly for the family, Gerhard's body has never been found.

"There's not a moment that goes by that we don't think of it, to be honest. I know it sounds like a cliche but it isn't...We're hanging in there and we have to see it through to the end," Paul Wagner said.

"We need to know where his remains are so we can give him a dignified burial, which is what every good man deserves."