'RHOBH' Stars Kyle Richards, Kathy Hilton, Dorit Kemsley All Have COVID

The COVID concerns pausing production on "Real Housewives of Beverly Hills" run way deeper than an infected crew member ... we've learned several cast members also have the virus.

Sources with direct knowledge tell TMZ ... Kyle Richards, Kathy Hilton and Dorit Kemsley have also tested positive for COVID-19. We're told they are all recovering at home and none of the women had serious symptoms.

The series started filming its new season toward the end of October, and our sources say there were safety protocols in place including testing and temperature checks ... but that couldn't stop a COVID outbreak from impacting production.

As you know ... 'RHOBH' shut down production last week after a crew member tested positive for the virus. Turns out even if the crew member was COVID-free, production would have shut down because nearly half the stars contracted the virus.

Our sources say Kyle, Kathy and Dorit did not contract COVID on set, but Kathy and Kyle were hanging out together -- after all, they're sisters -- and Dorit was along for the ride.