Sydney Sweeney has revealed a sneak peak at her transformation into a female boxing star for her latest film role.

The American actress, who appeared in romcom Anyone But You earlier this year, is set to portray former US champion boxer Christy Martin in an upcoming biopic.

In new images shared to her Instagram, Sweeney can be seen leaving her blond hair behind for a brunette curly wig.

The 27-year-old also dons a baggy, red vest and grey sweatpants in the pictures which see her standing outside a film trailer as well as posing beside a production chair with the name “Christy Martin” written on it.

“Well the cats out of the bag thanks to some paps in bushes so here’s a little bts (behind-the-scenes) from my film I’m working on right now,” she wrote alongside the images.

“Over the past few months, I’ve been immersed in training to bring to life the story of an incredible woman — a true champion who fought battles both inside and outside the ring.

“Her journey is a testament to resilience, strength, and hope, and I’m honored to step into her shoes to share her powerful story with you all. more to come soon.”

Directed by Australian filmmaker David Michod, the film will tell the story of Martin, who rose to fame as one of America’s most successful female boxer in the 1990s.

She won the World Boxing Council super welterweight title in 2009 and was the first female boxer elected to the Nevada Boxing Hall of Fame.

Sweeney rose to wider prominence with her role in the HBO drama series Euphoria alongside Zendaya, which first aired in 2019.

She earned an Emmy nomination for her role as Cassie, as well as for her appearance in the first season of the anthology series The White Lotus.