Upal, winner of 2012 Miss India UK crown, hails from Birmingham and had done modelling assignments in India and Britain. On the show, she has been adderesed as a "piece of shit" by one of the housemates - Conor McIntyre.
After watching the show, 1, 200-plus viewers filed complaints against the racits remarks to Ofcom, Britain's television regulator and it has mounted a probe.
The incident occurred on June 25 episode and many viewers thought that McIntyr's behaviour amounted to bullying, reports hollywoodreporter.com.
McIntyre has been warned about his behaviour by Big Brother producers after he used a string of expletives.
In another episode, aired on June 28, a female housemate called a black contestant "ridiculous gorilla" with "no sanitation" and Ofcom said it registered 114 complaints from viewers about the remark, which was perceived as racist.
A Channel 5 spokesman said the broadcaster is committed to complying with Ofcom's broadcasting code and "will help to facilitate a speedy investigation into this particular episode of 'Big Brother'."