St George captain and five eighth, Trent Barrett has been found not guilty by the NRL judiciary on a grade two contrary conduct head-slamming charge.

Barrett was placed on report by referee Matt Cecchin for a head-slam on winger John Olzard in the 46th minute in Saints' 58-16 win over South Sydney last weekend.

The verdict means that Barrett will be available for rounds 25 and 26 of the NRL premiership, Saints having a bye in round 24.