The 42-year-old rapper - whose real name is Cornell Iral Haynes Jr - has maintained his innocence and insisted he was "beyond shocked" to be arrested last weekend after a 21-year-old college claimed he had sexually assaulted her on his tour bus after a gig in Auburn, Washington.
And now, according to the woman's attorney Karen Koehler, she has asked the authorities to "put a halt to the criminal investigation of [Nelly]." Koehler added: "She will not testify further in a criminal proceeding against him."
In a letter, obtained by TMZ, Koehler went on to explain that her client was devastated that her rape allegation was made public so quickly and she feels that she cannot take on a celebrity and win.
The lawyer added: "Who will believe her. People are saying horrible things already. She cannot handle this. She is about to break.
"Every step of the way since she called 911, she wishes she had not. Not because what happened didn't occur exactly the way she described. Not because she did not want the police to charge the celebrity with alleged rape.
"She wishes she had not called 911 because she believes the system is going to fail her.
"She wonders who is she to go by her small unimportant self against a celebrity. Who will believe her? People are saying horrible things already. She cannot handle this. She is about to break."
Nelly was booked on second-degree rape charges after the woman reported the alleged incident, but the 'Dilemma' hitmaker's lawyer insisted her claims were "completely fabricated".
His lawyer said in a statement: "Nelly is the victim of a completely fabricated allegation.
"Our initial investigation clearly establishes this allegation is devoid of credibility and is motivated by greed and vindictiveness.
"I am confident, once this scurrilous accusation is thoroughly investigated, there will be no charges. Nelly is prepared to address and pursue all legal avenues to redress any damage caused by this clearly false allegation."
And the 'Hot in Here' hitmaker suggested he will be taking legal action against his accuser.
He tweeted: "I want to thank my fans for their unwavering support. They know me.
"I assure you I will be vindicated. And I assure you, I will pursue every legal option to address this defaming claim. Thank you.
"In other words all know damm well I ain't do no dumm S**t like this..!! Love ..!!!! (sic)"