Securing some of the world's most recognizable sex symbols to pose for photo shoots has been a key strategy of Playboy, allowing it to sell millions of copies - sometimes with the allure of a single model. Many of the most in-demand women are also reluctant to appear in the magazine, however, leading Playboy to make big offers - some reportedly in excess of $1 million - to encourage well-known celebrities to pose for featured spreads. In the most recent example, troubled actress Lindsay Lohan had reportedly been offered close to $1 million to appear in Playboy.

When contacted, Playboy would not comment on offers made to prospective celebrity models, but many have confirmed through news outlets and celebrity publications that they have been offered large sums to appear in the magazine.

So, which celebrities have reportedly been offered huge sums to appear in Playboy? Which have turned them down? Click ahead to find out.