A blind person, a Buddhist and a Girls Aloud reject... it must be Big Brother time

The ninth series of the controversial programme is understood to be returning to its roots as a social experiment but insiders say that Channel 4 is planning to push more boundaries than ever in a bid to boost ratings after last year's lacklustre performance.

Girls Aloud reject: Stephanie McMichael is believed to be one of 16 contestants believed to be in hiding ahead of the launch show

Housemates will include a woman who has had a breast enlargement, a blind person, someone who has been deported from America, a Buddhist and a Muslim.

It has been revealed that one of the housemates is already a reality reject having been thrown off Popstars: The Rivals, the programme which created Girls Aloud.

One source close to the production told the Daily Mail: "I think the claim will be that this is a show that is going to highlight all parts of society and how people from different worlds interact with each other. The reality is – it is going to be something straight out of the circus.

Contestant? London chef Rex Newmark is also rumored to be on the show

"They have picked people that are going to clash and some who have had really difficult lives – I wouldn't be surprised if charities were on the phone as soon as it starts. It is going to be like something out of one of Barnum's freak shows."

Barnum's exhibitions of people that were physically and mentally different to the rest of society were popular in Victorian times, but because of social and medical progress by the mid 1950's they had fallen out of favour.

A spokeswoman for Channel 4 said: " We don't pass judgement on the housemates. We will leave it up to the viewers to make their own minds up once the show has started."

Queen BB: Davina McCall will be back to grill the house mates as they are ejected from the house

It will not be the first time the broadcaster has come under fire over the type of people puts in the house and its duty of care towards them.

In 2006, influential mental health charity protested to Channel 4 at the admittance of vulnerable people into the Big Brother house following contestant Shahbaz Choudhary's threat to kill himself.

Dr Andrew McCulloch, the chief executive of the Mental Health Foundation - which helps people survive, recover from and prevent mental health problems – told Channel 4 boss Kevin Lygo the reality TV show reinforced negative stereotypes of people with mental illness, feeding discrimination and making sufferers a "laughing stock" while having little regard for the health of the contestants.

The clink: Big Brother housemates will be sent to this tiny cell for punishment if rules are broken

It's back: A new round of housemates will enter the compound tonight as the ninth episode kicks off

Last year the broadcaster was forced to air three public apologies after Celebrity Big Brother attracted 54,000 complaints from viewers over the alleged racist bullying of Shilpa Shetty, an Indian housemate and Bollywood actress.

It led to a diplomatic incident that overshadowed Gordon Brown's visit to India. Ofcom ruled that Channel 4 had breached the broadcasting code with 'serious editorial misjudgments'.

It has since axed the celebrity incarnation of the franchise, opting instead to just air a teen version on digital channel E4 earlier this year.

The broadcaster's deputy chairman Lord Puttnam has admitted he is 'not proud' of the show.

He said in a speech at the Hay-on-Wye literary festival: " am not proud of the Big Brother row – I am not even proud of Big Brother.

But Big Brother accounts for 15 per cent of the total revenue that keeps Channel 4 afloat."