It should only be ex NZ and ex USA as they are the only two exempt countries.
Aviation Transport Security Regulations 2005, Authorised Version F2018C00068 registered 19/01/2018:
"exempt country means New Zealand or the United States of America"
This is is one of my biggest gripes returning to my country and i almost detest having this often over the top search being done what i skeptically believe is for the Duty Free shops port side. And it came to bear the other month when some fragile metallurgical samples, which had passed x-ray, were broken by the overzealous handcheckers. I had to pack them tightly and small enough not to be like a bottle, but of course they would not listen. I've been brewing on this for a while and it came to a head over this incident and in point form;
1) Austman, they do not check in TPE, ICN, HND or NRT. I'm not sure on the LHR to PER. (So is our great government saying that all the other airports that we re-search your items useless? So SIN and BKK are incompetent? We, the Australian Government cannot trust your security measures. Is it because the other airports told them to "stick it" and they will not do the searches? )
2) So why don't we do it when we fly OUT of the country? (is our checking far better than other countries? Oh i forgot we just revamped our expensive shopping malls, sorry, sorry, I meant departure halls, spending millions, but dumping the arrivals out in the smoking area!)
3) So why don't we do it for internal flights? Why not, oh sorry i forgot that we have better checking than SIN at all our airports!
4) I'm not a believer in conspiracy theories (like paying 40,000 very passionate NASA staff bribes to keep them quiet about the staged moon landings!!!) but i wouldn't argue the negative that its to funnel business to the duty free shop upon landing. Going out now its almost an embarrassment as you hurdle the shop counters trying to make a shortcut to the lounge without going through the chicanes, almost deserving of a Monty Python skit. So why not help the incoming Duty Free? Mmmmm, so where do a lot of the tourists buying booze come from, surely not Thailand or Bali or Malaysia.......
Sorry for the rant, but its in my top three list of what I hate most when travelling.