The 48-year-old, who was born as male Andrew 'Andy' Wachowski, was intending to keep her transition quiet, but feared her new identity would be uncovered by the press.

Lilly is part of a dynamic sibling directing team with Lana Wachowski, who also came out as transgender in 2012. The pair have made many movies together, including The Matrix, Cloud Atlas and Jupiter Ascending.

In a statement titled "SEX CHANGE SHOCKER—WACHOWSKI BROTHERS NOW SISTERS!!!" on Windy City Media Group, Lilly describes how she has been waiting for such a headline to be published in the media so she wanted to tell her story herself.

"So yeah, I'm transgender," she writes. "And yeah, I've transitioned... I'm out to my friends and family. Most people at work know too. Everyone is cool with it. Yes, thanks to my fabulous sister they've done it before, but also because they're fantastic people. Without the love and support of my wife and friends and family I would not be where I am today."

"I knew at some point I would have to come out publicly," she explained. "You know, when you're living as an out transgender person it's… kind of difficult to hide. I just wanted – needed some time to get my head right, to feel comfortable. But apparently I don't get to decide this."

Another reason why Lilly chose to tell the public herself about her transformation is because she thinks the words 'transgender' and 'transition' have "lost their complexity in their assimilation to the mainstream".

"My reality is that I've been transitioning and will continue to transition all of my life, through the infinite that exists between male and female as it does in the infinite between the binary of zero and one," she explained. "We need to elevate the dialogue beyond the simplicity of binary. Binary is a false idol."