Former Big Brother contestant Dawn Blake has said she is going on hunger strike until the show's producers hand over tapes of her time in the house.

Dawn, 38, said in a statement she had been kept in the house against her will, and wants unedited footage from the programme to support her claims.

Dawn, from Birmingham, was thrown off the show on Thursday after a week for communicating with the outside world.

Channel 4 stressed the welfare of contestants was of utmost importance.

In her statement, released on Wednesday, Dawn said she had already asked to leave the house because the show's producers would not hand over her suitcase.

The case contained lotions needed to treat the skin condition eczema, she said.

The "exercise scientist" also claimed the programme had been edited to show her in an unfavourable light, suggesting that she did not wash during her time in the house.

"I was smeared by the production team as a smelly cheat," she said.

Exploitation

Marjorie Wallace, chief executive of Sane, said more robust selection tests were needed to prevent vulnerable people from taking part in the show.

She is also concerned that viewers will think watching someone suffer a mental breakdown is "harmless entertainment".

This year's contestants have included Shahbaz Chauhdry, who threatened to kill himself during his stay.

'Sinister echoes'

The 37-year-old Glaswegian walked out of the Channel 4 show after just five days.

This year the Big Brother house is smaller than in previous years, with greater use of mirrors and glass to give contestants as little privacy as possible.

Ms Wallace said she considered the environment and conditions experienced by the housemates as reminiscent of psychological experiments.

"Big Brother is playing fast and loose with people's minds - and lives," she said.

"Manipulation of people at risk may not only cause long-lasting damage to them, but to viewers who are led to believe that watching mental distress is harmless fun.

"It is both dangerous and unjustifiable."

Channel 4 was unavailable for comment but the broadcaster has previously defended its procedures, stressing that the contestants' welfare is "of the utmost importance".

The show's producers said all contestants were "intensively screened by professionals" before entering the house.

Psychologists are also available during the show's run to discuss any concerns that could not be resolved, they added.