Mining services entrepreneurs Peter Bartlett and Ron Sayers face the prospect of a new trial next year after a jury was unable to reach a verdict on tax fraud charges.
The 12-week trial resulted in the conviction of one of their co-accused, tax scheme promoter Greg Dunn, and the acquittal of a fourth defendant, junior accountant Deborah Grace.
The jury advised today it could not reach a unanimous verdict, one day after telling Justice Eric Hennan that was the likely outcome.
Justice Heenan then discharged the jury from what he called a "long, difficult and important case".
Justice Heenan said Mr Bartlett and Mr Sayers were released on bail and ordered them to appear at a directions hearing on November 28.
About 60 supporters of Mr Bartlett and Mr Sayers were outside the court and Mr Bartlett was clearly relieved at the court's decision, although both he and Mr Sayers declined to comment.
The prosecution, led by senior counsel Paul Roberts, now has to decide whether it wants to pursue a retrial.
Following the jury discharge, Ausdrill announced Mr Sayers will resume all duties as managing director immediately, a position he had kept during the trial but was restricted from doing daily tasks.
Ausdrill's shares were down 1.2 per cent today, at 97.5 cents.
