The furore over alleged racism on Big Brother has put reality TV under scrutiny.
But the Channel 4 show has become used to disputes during its seven-year history in the UK.
The Big Brother house erupted into a late-night drunken brawl during the fifth non-celebrity series in 2004.
Ofcom upheld complaints after a fight in the house in 2004
When housemates Victor and Emma squared up, live coverage was cut, security guards entered the house, police were called and an eviction was postponed.
Ofcom upheld 55 complaints about the live coverage, saying the fight was too violent and not stopped soon enough.
But the regulator rejected 190 more complaints about edited footage of the dispute that aired the following night.
Last year's Big Brother 7 was accused by fans and health groups of exploiting housemates and neglecting their welfare.
Pete Bennett became the winner of the seventh series in August
Concerns were raised over Pete, who has Tourette syndrome and went on to win, and Shahbaz, who threatened to kill himself after five days in the house.
The Mental Health Foundation said Channel 4 appeared to be "exploiting vulnerable individuals to make a TV show".
But Ofcom said the show stayed within the bounds of acceptability and did not breach the broadcasting code.
PHONE VOTE ANGER
When four evicted housemates were reintroduced to Big Brother 7, more than 2,600 people complained to premium rate phone line watchdog Icstis.
Nikki was among four contestants allowed back after being evicted
They claimed to have been misled after paying to evict Grace, Lea, Mikey and Nikki once - only to see them return.
Icstis upheld the complaints, saying there was an "unprecedented number" and "undoubted strength of feeling".
Channel 4 admitted the oversight. It escaped a fine but was ordered to pay almost £50,000 in administrative costs.
Future finals will be broadcast with a delay after housemates were heard swearing before the watershed during the Big Brother 7 climax.
Ofcom upheld two complaints over three separate incidents of bad language from Nikki and Aisleyne during the finale.
About 900,000 children were watching at the time, Ofcom said. They ruled that evictions raised "tension and the possibility of extreme reactions".
Channel 4 undertook "a serious review" and decided to implement the delay.
In 2005, Ofcom said Big Brother 6 operated "at the limits of acceptability".
Contestant Kinga's conduct drew several complaints from viewers
Some 887 complaints were received about the series - with 259 relating to Kinga simulating sex with a wine bottle.
Others objected to Makosi and Anthony getting intimate in a hot tub. Ofcom raised "serious" concerns - but said the scenes did not break its code.
And presenter Davina McCall was cleared of racial discrimination over what some viewers called a hostile interview with Zimbabwean Makosi.
The last series of Celebrity Big Brother was marked by bitter exchanges between entertainer Michael Barrymore and politician George Galloway.
MP George Galloway famously impersonated a cat on the show
During an argument, Mr Galloway taunted Barrymore, a recovering alcoholic, with the phrase: "Poor me, poor me, pour me a drink."
The MP was also heavily criticised by constituents who felt he abandoned them and should have been in Westminster.
But that was all overshadowed by his infamous impression of a cat.
BIG BROTHER 'BULLY'
After walking out of the celebrity show in 2005, Germaine Greer accused Big Brother of acting like a playground bully.
Greer tried to persuade housemates to stage a naked rebellion
She said producers' "superior" tactics like making housemates cold and hungry could encourage school bullying.
"It was demonstrating the role of taunting in the playground," she said, charging Big Brother with behaving "like a child rather than a parent".
Greer left the show after failing to persuade other contestants to stage a naked protest against Big Brother.
After Big Brother landed in the UK in 2000, it did not take long for controversy to rear its head.
"Nasty" Nick Bateman was booted out through the back door
"Nasty" Nick tried to influence the nominations by writing notes and showing them to fellow contestants.
But his housemates confronted him in a moment of high drama that gripped the nation. Eventual winner Craig told Nick: "I just thought you were genuine.
"I was misled and you made me look a fool." Channel 4 threw Nick out for "persistent infringement" of the rules.