London, Jul 17 (IANS): Dame Helen Mirren has a "filthy" sense of humour, her co-star Jason Bartha from "National Treasure: Book of Secrets" has said.

The 64-year-old actress stunned Bartha with her saucy quips and crude remarks when they worked together, but he admits he found her confidence "sexy", reports femalefirst.co.uk.

"Helen is the only person I've ever worked with that I've had a crush on. She's so sexy, smart and talented and loves having fun but if I thought Catherine Zeta-Jones was bawdy, Helen was filthy," said the actor, who stars with Zeta-Jones in an upcoming movie "The Rebound".

"There was a scene where Nicolas Cage had to stick his hand in a crevasse and pull a lever and while he was doing it, she leaned over and said something so suggestive, all I could do was look at her in shock and say, 'Dame Helen!'."

"But she loves having fun and the fact she's so comfortable in her own skin is what makes her so attractive," he added.