6:01 PM PT -- In a revised statement, a rep for Trey tells TMZ ... "Earlier today, the attorney who drafted this suit was credibly accused of trying to pay a woman to falsely accuse Trey. Hours later, that same attorney has filed this suit on behalf of an anonymous client. It isn’t hard to see what’s happening here, and it is a shame for genuine victims of sexual assault.
The rep adds, "the allegations in this complaint are false. Trey looks forward to having the facts fully aired.”
Trey Songz allegedly anally raped a woman at a house party ... this according to a new $20 million lawsuit.
The singer is being sued by a Jane Doe who says she had a consensual sexual relationship with Trey before the alleged rape on March 24, 2016 ... when she claims he suddenly turned into a "savage rapist."
According to the lawsuit, obtained by TMZ, the woman claims Trey invited her to a house party in L.A., where he invited her upstairs for what she believed would be consensual sex.
Instead, she claims Trey repeatedly asked her if he could "get that a**" on the way upstairs ... to which she says she repeatedly told him "no" and to stop asking.
In the docs, the woman claims Trey's demeanor changed upon entering the bedroom ... she says he threw her to the ground, ripped her pants off, pinned her down face first and forced his penis into her anus without her consent.
The woman claims she screamed in pain and begged Trey to stop, and even tried fighting him off her ... but says she was overpowered.
In the suit, the woman says someone entered the room during the alleged rape, giving her hope that what she describes as a "brutal rape" might end ... but she says the person quickly left the room and Trey kept raping her.
The woman claims she was only able to escape after Trey finished and stopped raping her ... grabbing her clothes, except for her underwear, and running outside to call an Uber.
In the docs, the woman says her Uber driver noticed she was in distress and rerouted her to a hospital, where she claims a sexual assault exam was performed and the police were called.
The woman says the exam showed she had "severe anal tearing that could require surgery" ... but she says she didn't name Trey to police because she was "in shock and fearing for her life."
She's now suing Trey for $20 million in damages.
The woman's attorney, Ariel Mitchell, is also representing 2 women who are suing Trey for alleged sexual assaults in Miami and Las Vegas.
As we first told you ... Trey's legal team is accusing Mitchell of witness tampering in the Miami sexual assault suit, an allegation Mitchell vehemently denied.
Mitchell and the woman's other attorney, George Vrabeck, tell TMZ ... "Victims are coming forward every day. Just know you are not alone, and this behavior is unacceptable. George Vrabeck and I will not be deterred by bullying or intimidation tactics and will continue our pursuit of Justice for sexual assault victims of Trey Songz.”
We reached out to Trey's camp about this latest suit ... so far, no word back.
Originally Published -- 5:11 PM PT