Transcript for Controversial Princess Diana Biopic Premieres in London
And burning up the "gma heat index" this morning. The movie about princess diana's final years. Naomi watt was on the red carpet for the film that she plays diana. And it's a role that made her so nervous, she turned it down twice. Your royal highness. Reporter: It's one of this year's most highly anticipated films. As crowds gathered for the premiere of "diana," many hoping to catch a glimpse of the look alike actress, par traying one of england's most iconic figures. From the diamond earrings, to the gown, naomi watts wowed the red carpet. In this case, I did it in the reverse direction. Starting with the look and the voice. I want to help people. It's a fantastic time for a film like this to make its debut. The royal family is so hot right now. The birth of a new heir. This film is coming off the back of all of that. Reporter: The new film centers around diana's secret affair with dr. Hasnat khan. The pakistani heart surgeon said to be the love of diana's life. It is a romance that has been shrouded in controversy, since the real-life dr. Khan told the "u.K.'S mail" that they are talking about a relationship they didn't know much about. But historically accurate or not, the 44-year-old actress tells the bbc it's a story she felt had to be told. I relate that last two-year period centering around not only the love story, but parallel to the great achievements to what she did in her work. We're interested and fascinated in the most famous woman of our time to this day. And that's a testament to who she was. "Diana" in theaters here. And naomi will be here on "gma." Interesting to see how the movie does. Katy perry sure has something to roar about. The new song is officially her eighth number one single.
This transcript has been automatically generated and may not be 100% accurate.