Nick Hewer has claimed 'The Apprentice' bosses have previously tried to influence when a contestant is fired based on their hair colour.
The 72-year-old TV presenter - who was an adviser to boss Lord Alan Sugar on the show for 10 years - has recalled producers once wanted a blonde candidate to remain in the process, but the businessman insisted he would fire them when he saw fit.
He told The Sun newspaper: "I say to him, 'Oh, by the way Alan, the blonde: he or she is as thick as a fridge door, and I urge you with every fibre of your being, get rid of them, because they're going to let you down.
"And the producers will say, 'Do you think you could find it in your heart to not get rid of the blonde just yet?'
"He will say, 'The blonde will go when the blonde deserves to go.' "
Nick has also claimed show bosses used to choose candidates for the programme based on their looks.
He said: "There was a time when all the young ladies who came on wore black pencil skirts and very high heels, with their hair done up in a chignon.
"If you've got 16 in an hour, you think, 'What are their names?'
"I suspect that the producers go for different looks or people that can be differentiated visually - that would make sense, wouldn't it? But again, you need the characters don't you?"
The 'Countdown' host insisted a vital part of the application process is to put something "outrageous" on your CV, and revealed the BBC won't allow a spin-off series about the winner to be made because it could look as though they were promoting Lord Sugar's businesses.
However, an 'Apprentice' spokeswoman has insisted Lord Sugar decides who gets fired and it is "not true" that candidates are chosen because of their looks or "single lines on their CV".
They said: "All firing decisions throughout 'The Apprentice' are down to Lord Sugar's own judgement, and solely based on his opinion about who he believes should be fired after every task.
"'The Apprentice' is a serious business reality series; the winner will be in partnership with Lord Sugar and therefore needs to have the relevant credentials.
"References are checked for business and education credentials and a business consultant is involved at audition stages. In addition to this, Lord Sugar sees the CVs during final selection process. To say that candidates are chosen purely for their looks or single lines on their CV is not true."
Nick was replaced on the show by Claude Littner in 2015, while Karren Brady took over from Margaret Mountford as Lord Sugar's other aide in 2010.
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