Perhaps this would be of interest to you:
https://stackoverflow.com/q/33346023/1919069. But for me, I am using Bruno's "dc-ore-packager", found here:
https://github.com/BrunoNZ/dc-ore-packager. You have to "Batch Import (ZIP)" though and note that it only links to the bitstream and doesn't download any ORIGINAL bitstream. That tool satisfies our use case which is to 'harvest' specific items only from a given community or collection so we are using it in our repository.