Rachel Reilly -- Ex-Big Brother Champ SLAMS Racist Houseguests

Rachel Reilly -- the 2011 "Big Brother" champ -- says she's "disgusted" by all of the racist and homophobic comments being made inside the BB house this season -- telling TMZ, "It makes me sick to my stomach."

Rachel has a vested interest in the show this season because her sister Elissa is one of the houseguests -- and is currently living with the people responsible for the bigotry.

We spoke with Rachel and her husband Brendon (another BB alum) who tell us they, like CBS, are offended by the hateful words that have been spoken inside the house.

"We think it's vile and disgusting and are completely horrified that people can even think such hateful things."