Tom Cruise’s secret Scientology girlfriend pre-Katie Holmes: Who is Nazanin Boniadi?

Until Saturday, most people had probably never heard the name Nazanin Boniadi. But after Vanity Fair released excerpts from its blockbuster expose on Scientology and how the controversial religion "auditioned" women from its congregation to be Tom Cruise's girlfriend in late 2004 (mere months before he stepped out with Katie Holmes), everyone has been buzzing about the Iranian-born, London-raised actress. But who is she?

[Related: Scientology 'auditioned' potential wives for Tom Cruise: report]

Soap operas fans probably know Boniadi well. For two years until 2009, she played Leyla Mir, a nurse who died from an airborne biotoxin, on "General Hospital." The role made Boniadi, who was nominated for a NAACP Image Award in 2008, the first actor to play a Middle Eastern character in daytime television, and the first Iranian-born actress to appear on an American soap opera. In February 2011, Boniadi landed a nine-episode arc on "How I Met Your Mother" as Nora, the love interest of Neil Patrick Harris' character. (Coincidentally, the woman who replaced her in Cruise's life, Holmes, also appeared on the sitcom as "Slutty Pumpkin" in October 2011.) In addition, Boniadi starred opposite George Clooney in a Nespresso commercial last November, and had minor parts in "Charlie Wilson's War," "Iron Man," and "The Next Three Days," which was directed by former Scientologist Paul Haggis, who has come out in defense of the actress and her arranged relationship with Cruise.

On Sunday, Haggis wrote an open letter to CNN's Showbiz411 confirming Vanity Fair's story about Boniadi, who has also "resigned" from Scientology. According to Haggis, Boniadi did indeed audition for the role of Cruise's girlfriend and then was punished after he dumped her in January 2005. (VF reports she was forced to scrub toilets with a toothbrush and dig ditches in the middle of the night, which Scientology adamantly denies.) "Naz was embarrassed by her unwitting involvement in this incident and never wanted it to come out, so I kept silent," writes the "Crash" director. "However I was deeply disturbed by how the highest ranking members of a church could so easily justify using one of their members; how they so callously punished her and then so effectively silenced her when it was done. It wasn't just the threats; they actually made her feel ashamed, when all she had been was human and trusting."

The Church of Scientology responded to Haggis' letter with a statement of its own, in which a spokesperson labeled him as "a status obsessed" traitor who is merely using his former religion to "grab headlines." The statement also goes on to speculate whether or not Haggis, who is married, and Boniadi are more than friends. "Did he reveal to you the relationship he was having with Nazanin Boniadi? We discovered this simply by Googling his name and hers. Here is our question: is it Paul Haggis who started a relationship with Boniadi while auditioning and casting his last film, 'The Next Three Days'? What is the motivation here?"

[Related: The rundown on Tom Cruise's three marriages]

When she's not busy with her acting career, Boniadi is also passionate about her activism with Amnesty International. As an official spokesperson, she campaigns for the safeguard of Iranian youth and women. In April of this year, she returned to her alma mater, the University of California, Irvine — where she earned a bachelor's degree with honors in Biological Sciences — alongside Rainn Wilson to support the Education Under Fire campaign, which works to end discrimination and persecution of the Baha'i religion in Iran.

Many of the posts on Boniadi's Twitter page (she has more than 5,400 followers) are dedicated to raising awareness about human rights and other tragedies all over the world, although she hasn't posted anything since August 31 … one day before Vanity Fair's story came out.

More Celebrity Features on Yahoo!:

Follow omg! on Twitter