Leonardo DiCaprio has said he was excited about the prospect of working with Dame Judi Dench on his latest movie.
The veteran British actress plays Leonardo's mother in Clint Eastwood's J Edgar Hoover biopic, starring Leonardo in the title role.
Hollywood hearthrob Leonardo, 35, described himself as "a fan".
"She's a sweetheart, she couldn't be more lovely. But as soon as the cameras start rolling and you hear that voice, it's powerful," he said.
"We had a scene where I am freaked out, stuttering, and her voice just froze my spine.
"She has a way of commanding a scene in a room, and it's just astounding."
Leonardo said of his lead role in the film, J Edgar: "This was one of the most challenging characters I'd ever seen on the page, and it was terrific to breathe life into this person, because he was such a mystery."
"Hoover was incredibly ambitious as a young man. He was highly motivated to succeed in Washington, primarily due to his mother's expectations of him."
:: J Edgar opens in cinemas on Friday January 20.