Renée Zellweger feels "safe" when physically transforming into roles.

Renée Zellweger on playing murderess Pamela Hupp

Renée Zellweger on playing murderess Pamela Hupp

The 53-year-old actress is taking on the role of real-life murderess Pamela Hupp - who is currently serving a life sentence for the 2016 murder of Louis Gumpenberger - in NBC series 'The Thing About Pam' and explained that having to don a number of face and body prosthetics for the project made things "easier" to play the part.

She said: "It's just another tool really, isn't it, to have the presentation match the narrative. I enjoy it because it makes it easier to transcend when you're telling the story on the day. I love it because it feels like a safe space to hide."

The 'Bridget Jones' Diary' star went on to explain that she feels she has "achieved" what she set out to in the new series and that she was "amazed" at what the makeup team were able to do to her.

She told PEOPLE: "I like [transforming myself] because the process is, when you're preparing, it's sort of a series of goals that you're trying to create this space, where you can tell the story, and that's such a big part of it. "And when it starts to come together, you can just tick the boxes as you get closer and closer to what it is, to creating this space to tell the story. So it just feels like, I don't know, that you've achieved what you've set out to do as it starts to come together and it's very helpful

" I was amazed. I was amazed at what they were able to achieve, what Arian [Titan, who designed the prosthetics] was able to achieve with his team of geniuses. "It was breathtaking to me that they're so talented and that he built these pieces from nothing just created them with his imagination, trying to create an approximation that would be appropriate in telling this story and being part of that was really cool."