The 69-year-old actress, who is backing Whitbread to win the jungle reality show, described the Olympic athlete as a "sensational example of a person who is exemplary".
Powers added: "Her life story is something that somebody should make a movie about. It's the kind of life story that other people might use as an excuse for their failures.
"She not only used it as a strength, and she is - in every aspect of the word - a champion."
The Hart to Hart star continued: "I think it would be a tribute to her - not only as a human being, but as somebody who has overcome such adversity and is a true champion - to win the show. I think she should be a hero in Britain, but she isn't and I don't know why.
"How many gold medal winners do you have that are alive and are such examples of superior citizenship? She is a true champion of sport and of life. She deserves every honour she can get."
Whitbread survived a bushtucker elimination battle against Pat Sharp on last night's I'm a Celebrity.
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