In what’s been described as an act akin to "eco-terrorism", more damage has been done to the predator-proof fence at Mulligans Flat Sanctuary.
The damage appears to have been made by a rogue group of activists - with Animal Liberation ACT again denying any involvement.
It follows the discovery on Monday of more than 30 holes made to the fence, designed to protect threatened species in the area from foxes and other predators.
Less than a day after the original vandalism was repaired, rangers on patrol at the sanctuary on Monday night discovered yet another hole torn into the fence.
ACT Parks and Conservation director Daniel Iglesias said in a statement, over the last two weeks there had been a ‘‘highly orchestrated’’ spate of vandalism in local nature reserves - which has conincided with the ACTs controlled kangaroo cull.
"This wilful vandalism is starting to border on eco-terrorism," Mr Iglesias said. "(It’s) putting at risk years of planning and research, not to mention an eastern bettong population which has just been released."
Animal Liberation ACT has denied any knowledge of the new damage and manager Bernie Brennan said his organisation did not condone the vandalism.
Mr Brennan said while they believed the ACT kangaroo cull was cruel and science behind it was wrong, Animal Liberation could not support an action that put more native animals at risk.
"We can understand their frustration... but it’s not the right way to go about it," he said."Cutting holes in a fence where there’s just been a new little species released is not productive to our cause... it’s not something Animal Liberation could support."
The organisation also denied any knowledge of the earlier vandalism.
Police are investigating and if caught the vandals could face fines of up $5500 and six months imprisonment.