Scarlett Johansson has admitted that she was terrified of Anthony Hopkins on the set of Hitchcock.

The 28-year-old actress plays the part of Janet Leigh to his Alfred Hitchcock in the forthcoming biopic which focuses on the filming of the celebrated director's most famous film, Pyscho.

Johansson says that she is still scared of Hopkins because of his role as serial killer Hannibal Lecter in Silence of the Lambs.

Speaking to Star magazine, Johansson said: ''You have to be brave to get into into the shower and face Anthony Hopkins as Hitchcock jabbing you in the face with a 12-inch kitchen knife. As much as he is a pussycat, Anthony is terrifying. Maybe I watched Silence of the Lambs too much when I was a kid.''

She says that playing a real person was challenging: ''I couldn't mimic her and I only did so much with the things that I picked up on. I guess it's your own interpretation of a person in some way because you want to do the person justice.

"I'm very excited about it. The cast is unbelievable, the script is so charming. I think it's going to be a great celebration of that era of filmmaking.''

Watch the official promo here: