Big Brother chiefs fear that the house is about to burst into a race war after a massive argument between contestants.
Show producers had to step in to calm tensions after Croydon gymslip mum Alex De-Gale let rip with a foulmouthed, slanging tirade against her housemates.
The 23-year-old accounts clerk lashed out at her fellow housemates Rachel and Rebecca after one of them overcooked a meal, reports the Daily Star.
Sylvia Barrie also joined in the ferocious row that left viewers shocked, and revived bitter memories of fights seen in previous series.
When Rachel tried to defend Rebecca, Alexandra unleashed a verbal battering that left her in tears.
She screamed: "You're getting on my f***ing nerves, you pr***. I don't give a f*** what you think!"
Stephanie McMichael was the only housemate brave enough to take on Alexandra and the two crossed swords in the most explosive scenes seen so far.
She snapped: "That's it. I might be 19, but I am not going to sit back and watch someone speak to someone else like that. It's completely out of order. No-one has the right to make someone else cry."
Stephanie added to Rachel: "Don't worry, she is not friends with a single person in this house."
Rachel was left so shaken, she was urged by others to report the incident to Big Brother.
Last year's series saw a furious race row between Shilpa Shetty, 31, and Jade Goody, 26.