Green’s Dictionary of Slang

(Aus. prison) a prison warder, who disciplines through kicking the prisoners.

1919		V. Marshall World of Living Dead (1969) 102: He’d left his mark on a couple of the pet ‘footballers’ when they come at the kickin’ game down in the Parramatta basement.
1921		D. Grant Through Six Gaols 51: One day while at work in the shop I heard a warder’s name mentioned and noticed that the term ‘footballer’ was applied to him. I discovered that this tide had been conferred upon him for his well-known habit of kicking prisoners.
1945		Baker Aus. Lang.