Thor: Ragnarok filmmakers are sticking to the script of the original Marvel comic books by making actress Tessa Thompson's superhero character Valkyrie bisexual.

The Creed star confirmed the sexuality of her character in a post on Twitter.com, weighing in on a fan discussion after one person claimed Valkyrie was "a big ole lesbian" in the original comics.

"She's bi," Tessa responded as she corrected the devotee.

The actress went on to brush off one man's complaint about her onscreen appearance as Valkyrie looking like a "typical sexless marvel tomboy" in early promotional footage for the upcoming Thor sequel, a remark which prompted other fans to laugh off his opinion.

Offering up her thoughts on Valkyrie's movie image, Tessa posted, "she cares very little about what men think of her," and expressed her delight at landing the part: "What a joy to play!" she added.

The sexuality news means Thor: Ragnarok will be Marvel Studios' first film to feature an openly-lesbian, gay, bisexual, or transgender (LGBT) superhero, although it's not clear if the blockbuster includes any explicit references to Valkyrie's sexual preference.

Chris Hemsworth reprises his role as the titular Thor in the upcoming release, which introduces Valkyrie as a warrior from his home of Asgard. Cate Blanchett portrays the main antagonist, goddess of death Hela, the first big female villain to appear in the Marvel Cinematic Universe.

Chris recently admitted he was initially a little apprehensive about working opposite the two-time Oscar winner, telling Vogue Australia, "It was sort of intimidating at first. Especially the lead-up to meeting her, I was like: 'OK, this is Cate Blanchett...!' My nerves were certainly more elevated than usual. No matter how many times I tell myself: 'I'm the lead, I'm the number one on the call sheet', it still feels like I shouldn't be; it feels like I've cheated somehow."

Thor: Ragnarok, directed by Taika Waititi, is released in November (17).