Baker Todd Mooney, 54, and his daughter Kirra, 10, were found dead after fire tore through a large shed at their home on Fenwicks Road, Biggenden about 12.20pm on December 20.
Mooney had been due to marry his long-term partner at the property this week.
Police have today revealed they believe the fire, which took several hours to extinguish, was deliberately lit.
The SES has helped search the property and a neighbouring paddock today as police investigate the deaths.
Anyone with information, CCTV or dashcam footage in the area at the time is urged to contact police.