The rapper – real name Robert Sylvester Kelly – has denied the allegations, but is now being probed by police in Georgia over a number of claims made in the documentary series Surviving R Kelly.
Now Gaga, who has been nominated for a BAFTA award for her A Star Is Born performance, has issued a quote promising victims of sexual assault that she is behind them “1000%”.
“I know they are suffering and in pain, and feel strongly that their voices should be heard and taken seriously,” she wrote in a Twitter statement.
Gaga and Kelly collaborated on her 2013 Artpop singer Do What U Want, which they performed together live at the American Music Awards and on Saturday Night Live.
She now wants their song to be removed from iTunes and other streaming services and has vowed never to work with Kelly again.
“As a victim of sexual assault myself, I made both the song and the video at a dark time in my life, my intention was to create something extremely defiant and provocative because I was angry and still hadn’t processed the trauma that had occurred in my own life,” she went on.
“The song is called Do What U Want (With My Body), I think it’s clear how explicitly twisted my thinking was at the time.
“If I could go back and have a talk with my younger self I’d tell her to go through the therapy I have since then, so that I could understand the confused post-traumatic state that I was in – or if therapy was not available to me or anyone in my situation – to seek help, and speak as openly and honestly as possible about what we’ve been through.”
She added: “I’m sorry, both for my poor judgment when I was young and for not speaking out sooner.”
Her statement sparked mixed responses, with many of her fans thanking her for speaking out.
“I have always been a fan of Lady Gaga and I always wondered why she did a song with RKelly, now I know. No one will ever understand what victims go through. I respect her and her decision to remove this song, thank you for using your voice to raise awareness on this,” wrote one.
Another tweeted: “I always feel in my heart that the ppl working on the album pushed him to be on the song to sabotage Gaga’s career but I’m glad she explained the situation and I hope haters will leave Gaga out of his bs and try to understand where she is coming from.”
But others were skeptical of Gaga’s timing, pointing out that her statement has dropped in the middle of awards season, where she’s likely to be feted for her Bradley Cooper-directed role in the box office smash A Star Is Born.