Ruby Rose. Picture: Instagram

Ruby Rose was criticised for "not being lesbian enough" when she was cast as Batwoman.

The 33-year-old actress - who identifies as lesbian and is also gender fluid - is set to star as the openly-gay titular superhero and her alter ego Kate Kane on the upcoming CW series but was shocked by the "backlash" she received from some fans.

She told Entertainment Weekly: "I came to the States to get into acting, and I couldn't even get a manager or agent, so I made a short film based on my life because I had the time to do it. I put it online, just to say, 'This is something I wanted to do,' and it went viral, which I didn't ever expect.

"And then I got an opportunity to audition for 'Orange Is the New Black' because they wanted to have a gender-neutral character. But I've also gotten backlash. 

"And that's when you realise you have to keep up with the terminology. When I got cast as a lesbian in 'Batwoman', I didn't know that being a gender-fluid woman meant that I couldn't be a lesbian because I'm not a woman - not considered lesbian enough."

While Ruby initially tried to brush off the criticism, the comments have made her think again about the way she refers to herself.

She added: "My initial response was 'Pfft!' And then I was like, 'Wait. Let me just figure this one out. How do I right this wrong, because if someone out there is upset by this, I need to know why and how to fix it.' 

"That's when I sort of said, 'I'm a woman that identifies as a woman. I'm not trans. But if being gender-fluid means that I can't identify as a woman at any point, then I guess I can't be that.' 

"Maybe I need to make up another term, one that doesn't step on any toes. One where I can be fluid in my gender, but also a lesbian, because otherwise I'm not sure what I am."