Celebrity Big Brother has now attracted 4,500 complaints about alleged racist bullying of housemate Shilpa Shetty.
Media watchdog Ofcom has received 3,500 - the highest number of complaints ever made about the show.
Channel 4 has received a further 1,000 emails and calls.
Angry viewers claim Bollywood actress Shilpa is being victimised by fellow housemates Jade Goody, Danielle Lloyd and Jo O'Meara.
In last night's episode, Jo declared that Indians are thin because they are always ill as a result of undercooking their food.
They also complained that Shilpa had touched other housemates' food with her hands.
Danielle sneered: "You don't know where those hands have been."
Allegations of racism first surfaced when Jade's mum Jackiey moved into the house.
She repeatedly referred to Shilpa as "the Indian" and refused to pronounce her name properly.
Jade's boyfriend Jack has also been accused of using a racist insult to describe Shilpa, which Channel 4 deny.
Channel 4 was forced to step into the debate and said it was monitoring the housemates for any signs of racism or bullying.
The broadcaster said in a statement: "The social interactions and dynamics of the group are one of the key parts of the Big Brother story and viewers have a right to see these portrayed accurately - however this is balanced with our duty not to broadcast material that may cause unjustifiable offence.
"We take this matter very seriously and Big Brother does not tolerate bullying or racist abuse in any form. Big Brother is closely monitoring all the housemates and will take appropriate measures to reprimand such behaviour where necessary."
Ofcom said the number of complaints had been driven by websites with forums devoted to Big Brother.
On www.digitalspy.co.uk, many viewers expressed their outrage at the treatment of Shilpa.
"As an Indian, I feel thoroughly ashamed. It seems racism is still rife in this country," wrote one.
Another said: "It makes me feel sad and ashamed. Why do people have to behave like this? And why do so many people find it easy to apologise and rationalise?
"I'm not calling it racism - but I imagine there are a great many Indians living in this country who certainly feel more isolated because of this and more fixed in their beliefs that this country would never truly embrace them."
Anti-bullying campaigners said Channel 4 should step in.
Mandy Telford, of trade union Amicus, told Sky News: "It is clear to everybody that Shilpa is being bullied and it is getting worse.
"Channel 4 and Big Brother are not doing anything. They are condoning this behaviour and it has an impact on people watching it - implying that this kind of bullying is OK.
"I think it has gone beyond just a story about Big Brother. Millions of workers are bullied on a daily basis and if they go home after work to see this on a TV show, they will think that maybe it is OK.
"Channel 4 should take a very clear line and stop this behaviour.
"It's about saying what is right in society and what is wrong."
An anti-bullying charity supported by Jade has dropped her from its website.
Jade has backed Act Against Bullying for the past two years.
But founder Louise Burfitt-Dons said her behaviour towards Shilpa was "unforgivable".
Housemate Ian "H" Watkins became so upset by the trio's treatment of Shilpa that he fled to the bathroom in tears.
The ex-Steps star said in the Diary Room: "I'm just a little disappointed in Danielle, she's been saying some really nasty things to Shilpa and just expects Shilpa to forget them.
"I just think she's being influenced by Jade. Jade's a lovely girl as well but I really think she isn't playing fair to Shilpa. Jade should know better.
"There's a lot of name-calling and petty things, and it's clearly schoolground behaviour. It's almost like bullying, and it's really, really unfair."
But friends of former Miss England Danielle jumped to her defence and insisted: "She's no racist."
Fellow model Leeandra Anderson said: "I can say 110% that Danielle is not racist.
"It's horrible to see her being accused of racism and I'm so shocked by what people are saying. It's not the Danielle I know.
"She would be mortified if she could see what's being written about her."
Ms Anderson, 21, from north London, added: "Out of 10 of Danielle's close friends, half of them are probably from different races and cultures. We've even got a friend who is half-Indian.
"I'm mixed race, my dad is from Jamaica, and Danielle has always been happy to eat spicy food at our house like jerk chicken. She's into all that. She likes to explore different things and meet different people. She went into modelling for that reason."
Another friend, 17-year-old Rochelle Wiseman, a former member of pop band S Club Juniors, also stuck up for Danielle.
"I can't believe Danielle is being labelled a racist. It's ridiculous.
"As a group of friends, we appreciate each other's cultural differences and if anything is said between us, it's as a joke. Danielle wouldn't mean anything in a horrible way," said Rochelle, from Romford, Essex.