Emma Greenwood had already been isolated from contestants

The 20-year-old was at the centre of a fight on the reality TV show on Wednesday, and had been isolated from the other contestants since then.

Police earlier said they were satisfied programme makers could guarantee the safety of the Big Brother housemates.

But Channel 4 and production company Endemol said they were concerned Emma's return could have risked more violence.

"We believe this is the best course of action to ensure the welfare and safety of all the housemates including Emma," a spokesman said.

But he said he did not think Emma was any more to blame for the fight than anyone else.

A review of the show was conducted when police received complaints after a fracas between housemates on Wednesday.

Worried viewers

The brawl broke out after Emma and another contestant, Michelle, were let back into the house after being moved to a "secret bedsit".

The show was taken off air for an hour and police received calls from worried viewers.

The planned eviction show on Friday night was postponed by Channel 4.

Bosses decided to delay the eviction until next week to help cool the heated atmosphere inside the reality TV house.

This week's nominations for Daniel and Vanessa will still stand and votes will be carried over to next week. There will be no nominations next week.

Earlier, a consultant to the reality TV show said he quit the programme because his warnings went unheard.

'Love you loads'

Criminologist Professor David Wilson warned that the reintroduction of Emma and Michelle back into the house would cause "conflict".

Professor Wilson, who works at the University of Central England, Birmingham, told Channel 4 News: "I realised that my advice hadn't been listened to, it was at that point I thought I should go.

"I was simply not prepared to lend my credibility to what was happening," he added.

Emma is the third person to have been asked to leave by producers in the history of the programme.