A jury has been dismissed four days into the cold case murder trial of Jay Brogden in North Queensland.
The 21-year-old was last seen in Airlie Beach in 2007.
His body has never been found.
Mr Brogden's mother and relatives packed the Supreme Court in Mackay this week to watch Jay Brogden's alleged murderer, 37-year-old Braddon Charles Peter Butler, stand trial.
Mr Butler has pleaded not guilty to the charge.
The seven-man five-woman jury was empanelled on Tuesday, but they were dismissed today under Justice David North after he found evidence given yesterday meant "a fair trial could not be heard".
Justice North told the court the mistrial was not due to any fault of Mr Butler, his representatives, or the crown.
The trial had heard from 14 witnesses, with up to 30 expected to give evidence.
Mr Butler is remanded in custody until his retrial in Mackay early next year.