Esme Bianco -- best known for her role as Ros on "Game of Thrones" -- claims she was drugged, tortured and raped by Marilyn Manson in a bombshell new lawsuit.

According to the docs -- obtained by TMZ -- the actress met the shock rocker in 2005 through his then-fiancee and he expressed interest in casting her in some film projects ... then she says he hit her up again after his divorce in 2007.

Bianco claims this is when he made his first "sexual overtures" toward her by requesting nude photographs, but he played it off as a joke. According to the docs, Manson flew her to L.A. in early 2009, purportedly to film a music vid for his song, "I Want to Kill You Like They Do in the Movies" ... and this is when years of abuse began.

The actress claims upon arrival she learned there was no film crew, just Manson, and she was expected to stay with him, be on call 24/7 and wear lingerie as her "costume." She alleges she was given drugs and alcohol and subjected to threats of violence and rape, and according to the docs ... was tied to a prayer kneeler and beaten by Manson with a whip he told her was utilized by the Nazis. She claims Manson also electrocuted her.

Bianco claims she was manipulated into believing this was all part of the music video shoot, and he assured her it was being edited. She says he then visited her in May 2009 in London and they began a sexual relationship, though she claims he was controlling and degrading.

According to the docs ... Bianco claims they kept a long-distance relationship going until 2011, when Manson convinced her to move to L.A. to live with him and promised her film roles. She claims during this time she endured constant abuse, including sleep deprivation, verbal abuse and tantrums if she expressed discomfort over the "violent and sexually graphic films" he allegedly played in his apartment.

She claims Manson once chased her around the home with an ax, and on another occasion "cut Ms. Bianco with a Nazi knife during sex, without her consent, and photographed the cuts on her body." She says he also posted the photos online without her consent.

Bianco says Manson used a pattern of using "drugs, force, and threats of force to coerce sexual acts" from her on multiple occasions, and claims he raped her around May 2011.

She also accused him of sexual battery during her time with him in L.A. in 2011. According to the docs ... "These acts include spanking, biting, cutting, and whipping Ms. Bianco’s buttocks, breasts, and genitals for [Manson's] sexual gratification," and all without her consent.

Bianco's lawsuit does not say if she reported the alleged rape or abuse to police. We've reached out to Manson's camp ... no word back yet.