Gentle Monster director Marie Kreutzer says Lea Seydoux's casting in the movie felt like a "piece of a puzzle falling into place".

The 41-year-old actress plays Lucy Weiss, a successful pianist whose life is shattered when her husband is accused of illegal child exploitation online, and former Bond girl Lea was the perfect person for the part, Marie said.

She told Gold Derby: "With every actress I was thinking about, it would've been a different film. So when Lea's name was brought up for the first time, it immediately felt right, like a piece of a puzzle falling into place. I had seen many of her films and had always admired her as an actress.

"We had a brief conversation on Zoom and it was clear after a few minutes. When working with any actor, you have to adapt to their way of working and have to find a common ground and a common language. And that's a big part of my work, it never gets old."

Marie also loved how "unpredictable" Lea was when it came to delivering a scene.

She continued: "With Lea, it was great because she's so in the moment when the camera is rolling; that is for me the most important quality of an actor to just really be there.

"I want to give actors a lot of space and flexibility for their own interpretation. I was always standing right by the camera, watching her -- not watching the monitor, but watching her, which I always do with actors -- and it was so unpredictable what she would do and how she would say the lines. Like, 'I forgot to breathe.'"

Another important casting in the film was Lucy's mother Eloise, with Catherine Deneuve taking on the role.

And while getting Catherine to sign on for the film could have been tricky, Marie said it actually ended up being a quick process.

She said: "The great thing about someone like Catherine Deneuve is that she doesn't have to give a s*** about what she's doing because she is a legend and an icon.

"Even more so in France than in the rest of the world. She can just do what she wants. We went for coffee and she immediately said yes.

"She had seen my previous film. She goes to the cinema every week. She's a real cinephile. She knows everything about films. She said, 'I've not shot a film in two years because there was just no good script and this script is really good and I want to do it.'"