Detectives allege 59-year-old Darryl “Blinky” Young, of Bogie, was behind the murders of Mervyn Schwartz and Maree Schwartz and her son Graham Tighe at the remote Shannonvale Station southwest of Bowen on Thursday.
Maree’s other son, Ross Tighe, survived and called the police after being critically injured.
9News has confirmed that detectives’ main line is whether a border fence dispute sparked the alleged incident.
Young’s property remained a crime scene Saturday.
It is believed to include a number of gold mine shafts from the 19th century.
Locals said they were in disbelief over the three deaths.
“People are just shaking their heads in disbelief,” Whitsunday regional councilor Mike Brunker said.
The family of Graham Tighe, including his partner and two children, made a journey of mercy to Mackay Base Hospital on Saturday.
They are there to support Ross, who remains in hospital in a serious but stable condition.
He has told the police his version of events.