The Senator has verified the authenticity of the images and made an apology via the ABC:
“I condemn this kind of juvenile behaviour, I’ve said to my volunteers many times, not to respond to the provocation that they’ve been getting during the campaign,” he said.
“We see unfortunately from time to time, stupid behaviour from volunteers and I put that in this camp, certainly I have no time for it.
“We’ve had people fined for damaging our signs, we’ve had people stealing our signs – that kind of behaviour is unacceptable, and responding to it in any way, even in juvenile sort of jokes, is unacceptable as well.
“I certainly apologise for any offence.”
Greens Senate candidate Christina Hobbs has posted her thoughts at some length to Facebook.