G'day DC,
I think you have your companies confused, easy to do with "Australian Helicopters", Helicopters Australia" and "Heliaust", among other "Aussie" company names
.
The Darwin contract is "Helicopters Australia" (read Helicopters NZ) with, I believe, a BK117 initially while they are waiting on their EC145.
The AS350B3 in Customs colours
AFAIK is replacing the B206L4 as the backup ship for the B412 on TI for "Australian Helicopters" (read Reef/Marine merger).
Cheers,
MPT