The victims' families were notified of the inquest date at the end of September.
Police would not comment on the investigation when contacted by the Herald yesterday because it had been referred to the coroner, but said last year the cause of the fire remained undetermined.
However a police media spokeswoman confirmed the police investigation was now closed.
Police engaged the services of an internationally-recognised independent fire investigator to review the fire investigation who agreed with the original findings, the Herald reported earlier.
The cause of the fire remains unknown.
Connor's mum Sharon Otto said it had taken a "ridiculously long time" and was pleased a date had finally been set.
"It will be good when the inquest has been and gone ... it's not going to change anything, but it's just the lead up to that next. It will be interesting to see what they have to say but I can't see it's going to be any more than what we already kind of don't know."
Otto was unsure as to why there had been a delay. "They did say these things take a long time, but even the police said it had taken longer than they thought and apologised and everything."
On the anniversary of her son's death she was getting through the day the best she could and said she preferred to celebrate his birthday in September.
"It's been a quiet day. I haven't done anything to be honest. It's one of those days where I try not to really think about it too much...
"Today is a little bit different. It's kind of hard to deal with. I'm just getting through the day."
Toni's brother Greg Johnston said their family and Toni's friends were still coming to terms with the huge loss.
"We're having a small get together tonight with a few of Toni's close friends to remember and celebrate her life.
"The inquest will be a tough time for our family but we hope it will bring some closure.
"The love and support from our family friends, Toni's friends and the wider community has been amazing, and has really helped us get through the difficult times," Johnston said.
