Kal Penn was impressed by his co-star Abbie Cornish's transformation into Anna Nicole Smith in Trust Me, I'm a Doctor.
A first-look image shows the Australian actress in a platinum blonde wig and a silver dress, in a detailed recreation of one of the late model's outfits.
The film, written and directed by Thane Economou, tells the story of Dr Sandeep Kapoor, Smith's doctor, who was charged with several felonies related to prescribing medications before she died of combined drug intoxication in 2007 at the age of 39.
He was cleared of any wrongdoing and acquitted of all charges after a nine-week trial.
Penn, who co-stars as Kapoor, told Variety he will never forget seeing Cornish for the first time in costume as Smith.
"She really embodied Anna Nicole in a very striking way," he told the outlet.
"She was a completely different person. I briefly met Anna Nicole a handful of times way back when I was starting my career, and she was on a reality show. I never really had any conversations of any note with her, but it definitely brought me back to that time. Abbie is excellent. She's phenomenal in this role."
The Harold & Kumar star also praised Cornish for avoiding doing an impersonation of Smith and focusing more on her heart, vulnerability and complexity.
"What made my job easier also is anytime you're in scenes like that, and you know my character is sort of responding to the Anna character, and then Abbie just walks in as Anna, my job is immediately easier," he added.
When announcing the role, Cornish said she was "beyond excited" to be working on the film, which is based on Kapoor's memoir Trust Me, I'm A Doctor: My Life Before, During and After Anna Nicole Smith.
Cornish rose to fame with 2004's Somersault opposite Sam Worthington before following it up with Candy alongside Heath Ledger in 2007. Her other notable roles include Jack Ryan, Sucker Punch, Limitless and Three Billboards Outside Ebbing, Missouri.
Trust Me, I'm a Doctor will be released in U.S. cinemas on 16 October.
