BULLETPROOF glass was shattered and a cell block office destroyed in what the union is describing as the worst riot at Maryborough prison in more than five years.
Corrective Services officers guarding the overcrowded S8 wing were forced to watch on as up to 10 inmates unleashed their fury on their surrounds, for several hours on Tuesday afternoon.
Guards told the Chronicle prison dogs were sent in to defuse the situation - a move generally accepted to be a last resort.
Together Union representative and former Maryborough prison guard Ian Barber says the fallout is that prisoners now have the upper hand in a battle of wills which is putting lives at risk.
Several inmates armed themselves with brooms and mops and used faeces as projectiles during the incident, according to several prison staff who spoke to the Chronicle.
While the guards were uninjured, one female staff member who was trapped inside the office was said to be "heavily traumatised".
Overcrowding had fuelled tensions at the prison for several months before the scenes witnessed on Tuesday unfolded, and Mr Barber said the State Government's response would either encourage or deter copycats.
"This has got to be addressed as a matter of urgency," Mr Barber said
"Prisoners have seen it happen and they will see it as leverage... next time it will probably be bigger."
Despite the reports, the Department of Justice insisted on Wednesday there "was no heightened risk".
Rejecting the term "riot" and instead labelling the event as an "incident involving a small number of prisoners", a representative said the "incident was effectively controlled and resolved" and further details could not be disclosed for "security reasons".
A CSQ spokeswoman dismissed claims this week that the jail was, at times, operating with a staff-to-prisoner ratio of 180 to two as "untrue".