Domestic Animal Services took custody of the dog that killed a Canberra woman this week for several days after an attack in August, it can be revealed.
The agency also attended, at least three times this year, the Watson house where Tania Klemke died - because of issues with dogs.
After a briefing from government officials about the attack, ACT Opposition leader Alistair Coe said officials had had custody of the animal for "a number of days in late August, early September" after it bit a person on August 29.
"It seems after this incident no orders, controls or conditions were placed on that dog as a result of that event. It seems that there might have been other events taking place at that same time as the dog attack but what we do know is the dog in question certainly did bite a person back on August the 29th and it went to Domestic Animal Services," Mr Coe said.
The victim of the August 29 attack is understood to have needed 42 stitches.
City services minister Meegan Fitzharris told ABC Radio police had now linked that incident to this week's fatal attack and she could give out no more information about it.
The dog named Simba had been shot in the ear by home intruders in March that had bashed and robbed Ms Klemke and had "trust issues".
But, despite knowing the dog was dangerous, Ms Klemke described Simba as her "best friend" because he "took a bullet" for her.
Mr Coe said Ms Klemke had been "let down" by the ACT's dangerous dog laws.
"Whether its an issue exclusively with the legislation or whether its an issue with the enforcement of current legislation remains to be seen but we simply cannot have situations where we have dangerous dogs, dogs that are known to have attacked people in the past released into the community," Mr Coe said.
"I think we need to change the default settings such that we have a situation where a dangerous dog causes serious injury to a person the default is not that they get released back into the community. The default is that they get put down."
In a statement, Ms Klemke's son Cody Baker described his mother as a beautiful, caring woman.
"Yesterday, I found out my mum has passed in a terrifying way from a dog that loved her so much!' He said. "I still can't believe it."
"I just keep thinking about her walking out the front door with a smile on her face happy to see me like she always did and Simba barking with over excitement.
"All I can think about is how it went down and I can hear her screaming for her life, it's terrible."
Twelve dogs have been declared dangerous since July, compared to 14 last financial year.
Ms Klemke had taken to keeping her dog inside the house as her back fence was damaged and it would often escape.
On one occasion late last year, neighbour Dieu Do said a dog she believed to be from Ms Klemke's property had scaled her fence and charged at her two young children.
"The fence was broken, even this year, I often hear [a dog] growling near my window, so I always lock up," she said. "I'm afraid for my boys."
On Thursday, a spokeswoman for Housing ACT said the government had not received any complaints or requests for maintenance about a fence at the Watson property.
"Housing ACT negotiates with private owners to repair [or] replace boundary fences where public housing properties adjoin a private home," the spokeswoman said.
The property will remain as public housing stock until a decision is made by Housing ACT on the best use of the land.
Housing ACT tenants are subject to the same pet ownership rules as all Canberrans, the spokeswoman said.
"Housing ACT does not impose any additional restrictions on pet ownership. As with all residents, public housing tenants are required to obtain and maintain all applicable licences and registrations."