Lady Gaga has apologised for collaborating with R. Kelly and has vowed to remove their 2013 single Do What U Want from streaming platforms.

A number of celebrities have been speaking out against the Ignition (Remix) hitmaker following the broadcast of Lifetime docuseries Surviving R. Kelly, which focuses on allegations of sexual abuse levelled against the singer.

Lady Gaga joined them on Wednesday night (09Jan19) by issuing a lengthy note on social media in which she apologised for working with him on the single and vowed to remove it from iTunes and streaming services.

"I stand behind these women 1000 per cent, believe them, know they are suffering and in pain, and feel strongly that their voices should be heard and taken seriously. What I am hearing about the allegations against R Kelly is absolutely horrifying and indefensible," she wrote.

"I can't go back, but I can go forward and continue to support... victims of sexual assault... I intend to remove this song off of iTunes and other streaming platforms and will not be working with him again. I'm sorry, both for my poor judgement when I was young and for not speaking out sooner. I love you."

She explained that when she made the song, taken from her album ARTPOP, it was "a dark time" in her life because she wasn't coping with being a sexual assault victim.

"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 continued. "I think it's clear how explicitly twisted my thinking was at the time... I share this not to make excuses for myself, but to explain. Til it happens to you, you don't know how it feels. But I do know how I feel now."

Back in 2014, the 32-year-old revealed that she had been raped when she was 19 and the incident left her with post-traumatic stress disorder, for which she now seeks therapy. In the note, she told her followers she would instruct her younger self to find professional help if she could go back in time.

Gaga, who performed the song with the R&B star at the 2013 American Music Awards, declined to appear in the documentary, according to producer Dream Hampton.