The 64-year-old was shot at close range outside his home at the Craignish Country Club, near Hervey Bay, on the night of August 15.
Harding may have been the victim of a botched robbery, police have said.
Two men have already been charged with his murder and the third was charged on Friday.
The 25-year-old man was arrested in a raid on his home at Crestmead, south of Brisbane, on Thursday.
He’s due to face Brisbane Magistrates Court later on Friday.
The two other men charged are Joshua Marcus Pope, 30, and Gregory Tremayne Pryor, 25.
“There are no further persons of interest sought by police in respect to the alleged murder,” Queensland Police said in a statement on Friday.
“All (alleged) offenders involved have now been charged with a number of linked property offences.”
The homicide investigation focused on an Isuzu four-wheel drive stolen from Maroochydore on the Sunshine Coast on August 13.
A week after Mr Harding’s death the car was driven to Hervey Bay and used in crimes there, including a ram raid at the Stockland Shopping Centre at 10pm on August 15, police said.
The 4WD was driven to the country club about 10.30pm that night.
It was later abandoned in Maryborough and set alight.
Pope and Pryer, both from Loganlea south of Brisbane, were arrested at Coomera on the Gold Coast and charged on August 22.Jump to next article