The jury began its deliberations on Thursday after listening to the evidence for more than two weeks.
Jurors were told Gerhard Wagner was last seen riding his motorbike about 3pm on January 7, after working on his yacht at a Brisbane marina.
He had a dinner date that night and had been planning to sail around the world.
But the former merchant seaman didn’t turn up for the date and his body has never been found.
The trial has heard Gerhard Wagner had considerable assets.
Prosecutors claim Robert Wagner owed Gerhard $84,000 and was in a difficult financial position before he disappeared.
It is alleged Robert Wagner murdered his uncle in the garage of the Ashgrove unit he lived in, which was owned by his uncle.
A witness, who cannot be named for legal reasons, came forward with claims Wagner told him he had killed his uncle and got away with it.
The jury began deliberations on Thursday afternoon.