removing a directory with hard linked files

i have 2 directory trees the appear to be hard linked replicas of each other. if that is true i want to totally remove one of them. but maybe there are files with no replicas or the replicas are in the same directory tree. it would seem reasonable to make a backup before doing this. but these are the backups and they are way too big to backup somewhere else. and i have lots of these to do. it's not about removing files; it's about making sure that rsync can remove a file when it brings in a replacement (e.g. that every file has just one link).

is there a tool that can verify that a directory does not have every link to any file?