Scarlett Johansson became deeply insecure while filming THE Black DAHLIA with British actress JEMIMA ROOPER - as the busty beauty wanted to be the only blonde in the production.

Rooper wore a blonde wig for her role, and although she was amused to hear of her co-star's "distress", it was no laughing matter for the LOST IN TRANSLATION actress.

Rooper says, "I heard Scarlett was very distressed when she saw my blonde wig.

"She thought she was the only blonde in the film."