Update at 6:07 p.m.: Revised to include new comments from the woman's attorney.

Dallas police are investigating a young woman's allegations that singer R. Kelly "knowingly and intentionally" gave her a sexually transmitted disease without telling her he was infected during an 11-month relationship that ended earlier this year.

Kelly's representatives did not immediately respond to a request for comment. A representative for the singer told the Washington Post he "categorically denies all claims and allegations" from the Dallas complaint.

His accuser, who is now 20 and has not been publicly identified, filed a formal complaint with Dallas police against the 51-year-old singer last week and intends to file a lawsuit by the end of the week, her lawyer says.

Dallas police said detectives with the Crimes Against Persons Division are reviewing the case with the Dallas County District Attorney's Office.

"When somebody brings something to our attention, we have a responsibility to look into it and to do our due diligence -- that's with any kind of case," Dallas police Dept. Chief Thomas Castro, who oversees investigations, said on Monday.

Police have said the incident will not be investigated as sexual assault since both parties consented. But in Texas, someone who transmits a sexually transmitted disease to someone else without disclosing it first can be charged with assault.

The woman's attorney, Lee Merritt, alleges R. Kelly's representatives invited the woman backstage at one of his concerts last year and he groomed her over the next several months to join a "sex cult" by paying for flights to his concerts and hotel stays.

The woman accuses Kelly of transmitting herpes to her during a trip to Dallas in December. She says she also met other women Kelly was allegedly involved with.

"She was tempted to simply free herself from the situation and not speak another word about it because quite frankly it's embarrassing to have become a part of that and to begin to be groomed into that lifestyle," Merritt said.

The woman decided to take legal action against R. Kelly after she tested positive for herpes earlier this year, Merritt said.

He said she belongs to an upper-middle-class family, which is supporting her, and doesn't want money from the singer. She wants him to get therapy and donate to causes for women who are victims of abuse.

"She wants to help bring this to an end," Merritt said. He added that he's keeping her identity under wraps because she's "deathly" afraid of becoming the face of her disease.

"She doesn't want this moment to define her," he said. "She's torn between wanting to hold him accountable and make sure he doesn't continue this behavior and wanting to move on with her life."

But her accusations are not the first against R. Kelly.

He went on trial in 2008 on child pornography charges, accused of videotaping himself having sex with an underage girl. He was acquitted.

A BuzzFeed News report last summer quoted parents and several women who alleged that he forms relationships with young women interested in the music industry and then mentally and physically abuses them. His attorney told the news organization then that Kelly denies the allegations.

The Associated Press contributed to this report.