We've learned the 21-year-old Seattle resident claims she met Nelly at a club in Washington, where she and her friends drank at his table and got "tipsy."

She says she was invited to an after-party and drove off with Nelly's people. The woman says she was taken to Nelly's tour bus.

She says she was in Nelly's room with him when he tried to have sex with her and she said no. She claims Nelly told her to "shut up" and said he wanted to have sex with her without protection, which she says he did over her objections.

The woman says, afterward, Nelly offered her money, but she declined, and then a woman came up and said, "You gotta go." She kicked her off the bus and threw $100 at her.

Nelly's lawyer, Scott Rosenblum, tells TMZ, "It does not surprise me that she wanted to have her story publicized. That is playbook 101 of a person with an agenda and clearly she has one. The agenda is money, fame and notoriety."

Rosenblum says he has an investigator on the case and "we will be able to show by objective evidence and unbiased witnesses that she has zero credibility."

The lawyer adds, "She's a person who is making a dangerous, fraudulent allegation to accomplish her own goals."