Channel 4 has declined to comment but the claims have gained fresh credibility after the personal details of some of the contestants were found on the Friends Reunited website.
A posting on CoolSmartPhone.com said: "We've already shown that two of the 'regular cadets' (Keri and Ryan) are in fact actors. However, there are other cadets; they're supposedly 'regular people' too, but we now have more details that they're not thanks to their entries on Friends Reunited.
The entry for Sarah-Jane Cass reads:
From: Northumberland Heath, Kent
Occupation: Currently studying media performance at Luton University
"When I left secondary school, I went to The Brit School of Performing Arts and graduated with three Distinctions last year and I am currently at the University of Luton, studying a degree in Media Performance and loving it loads!
"I'm working in Greece over the summer, and I am still loud as ever, that will never change! I have been working for ITV on a new series called Brainiac which starts in June 2005, and have my own radio show as a presenter on Luton FM, a local station, not hit the big boys yet!"
The entry for Billy Jackson (who made it into the final crew) reads: "How are you all doing? My life is pretty hectic at the mo, after someone stole the idea for my book, I turned my interest to acting. I have just finished filming Troy, with my new-found buddies Brad and Orlando. I would just like to thank Mrs Glean, you were my inspiration man."
Meanwhile another contestant has been spotted as an extra in a television advert.
Numerous postings on the forum run on Channel 4's Space Cadets website have also suggested that the programme is a sham.
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