Tenant versus Occupant

I am on the Board of an HOA in Texas. Our Bylaws prohibit sub-letting. We have a situation where an owner has a tenant with four (unrelated) adult "occupants". Their position is that their tenant is not "subletting" and that the four permanent "occupants" are allowed without being on the lease. Opinions?

Also not a lawyer here.
I think unless you have proof that the one tenant is receiving money from the four other occupants in exchange for living in the house and/or they have formalized the living arrangements in sub-leases or other sort of "contractual" document, then you're outta luck.
That said, while likely not in HOA documents, perhaps there is something in your state HOA laws and/or local or state codes that would prohibit five unrelated persons from living in a single house. So look beyond your HOA docs if you are trying to prevent this situation from occurring.
I could be totally wrong, but I've always heard that PA has such a law, which is mostly historic, but intended to prevent establishment of brothels.