Matrix filmmaker Lilly Wachowski, formerly known as Andy Wachowski , has revealed she is a transgender woman in a powerful essay titled "Sex change shocker – Wachowski brothers now sisters!!!"

Lilly Wachowski, 48, said in the essay published in Chicago's Windy City Times, she decided to go public with her announcement after a reporter from the U.K's Daily Mail attempted to pressure her into an interview about transitioning.

Wachowski, known for films like the Matrix series, V for Vendetta and Cloud Atlas, made the announcement four years after her sister and collaborator, Lana Wachowski, revealed she was a transgender woman.

"I knew at some point I would have to come out publicly," she wrote. "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."

In the essay, she said the journalist, identifying himself as a reporter with the Daily Mail, arrived at her door on Monday night asking her to reveal her gender identity for an article. She referred to the incident as a "threatened public outing against my will."

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Wachowski slammed the Daily Mail's history in dealing with transgender issues, specifically referencing the death of Lucy Meadows, a primary school teacher and transgender woman who took her life after the Daily Mail published a column titled "He's not only in the wrong body … he's in the wrong job".

"The reason I knew about her wasn't because she was transgender, it was because three months after the Daily Mail article came out Lucy committed suicide."

The Gay & Lesbian Alliance Against Defamation (GLAAD) applauded Lilly Wachowski in a statement and published guidelines for reporting on transgender issues.

"GLAAD is thrilled that Lilly Wachowski is able to be her true and authentic self today, however, she should not have been forced to disclose her transgender identity before she was ready to do so," said Nick Adams, GLAAD's director of programs for Transgender Media.

"Journalists must learn that it is unacceptable to out a transgender person, in the same way it is unacceptable to out a person who is gay, lesbian, or bisexual."