Actually, in the region (unless there are some on private hunting ranches, but I think there aren't). Have they made any plans to import more, because this isn't a suitable founder population (hint: Taronga Zoo, dhole)?
I think these were billed as a 'test import' and as it worked well, to the best of my knowledge, more should be imported in the future. They are actually the ZAA's highest priority antelope species, which means that their importation is more important than that of any other antelope species, a bit weird given how many antelope species need rescuing at the moment (bongo et al.).