I received a speeding fine including 1 demerit point for going 70kmph in a 60 zone. A number of people have told me that you can challenge a fine when it is 10kmph over the speed limit as there is a tolerance to allow for innaccuracy of cameras. Is this correct?
I agree with Rob, and if you want to challenge it, it will be up to you to prove that the speed camera is faulty. Good luck with that! The other point is that if authorities don't want to give you infringement because you were above the speed limit by 10k/h, this is their choice, they decide whether to issue an infringement or not, it is not up to you and you can not claim that they gave someone and did not give you, their choice, you were above the speed limit, so you were at fault.
If you have a good driving record, this would be your best bet, ask for review as Rob mentioned.