Lady Gaga is blocking Cher from releasing her duet with her.
Gaga donated a track she wrote, 'The Greatest Thing', to the 67-year-old diva, which they then recorded together, but the results have never been aired.
When asked by a fan on twitter why the song has not been released the song, Cher wrote: "It's done & she [Gaga] doesn't like it, or want it to come out. She's an artist, it's up to her. I'm disappointed 2 (sic)."
The producer behind the track - regular Gaga collaborator RedOne - previously said the song was something he and Gaga had worked on together, but remained unfinished until he played it to Cher.
He said: "Gaga and I recorded the song a few years ago, and we were always in the studio enjoying that song. It's weird we never did anything with it.
"So I remember my management and Cher's management were trying to get us together, and I thought, 'Oh my God, I'd love to meet Cher, just to meet her!' And so I met her, I played her some songs, and I played her 'The Greatest Thing,' and she loved it. She said, 'This is my song.' "
Originally Gaga was happy for Cher to record the track and to appear on the remix, but with RedOne's encouragement it became a duet.
He added: "I cut the vocals with Cher first, and I was in Madrid and got a text from Gaga saying, 'I'm thinking about jumping on the song in the remix.' "
"I was like, 'No, you should jump on the original! Make it a duet.' She said, 'Oh yes, OK, absolutely,' and then I spoke to Cher, and it became a party."
Cher is set to release her 26th studio album, 'Closer To The Truth' - her first since 2001 - in September.