Madonna appears to have taken a swipe at Lady Gaga in leaked video footage taken during rehearsals for her 'MDNA' tour.
The 53-year-old singer took a pop at her younger rival as she performed 'Express Yourself' on stage in Israel before launching into Gaga's 'Born This Way', which has often been accused of being overly similar to her own song.
Madonna then seemed to confirm that she was making a dig at Lady Gaga by singing 'She's Not Me' from her 2008 album 'Hard Candy', in leaked video footage which has appeared on YouTube.
This isn't the first time Madonna has referenced the similarities between the two songs, calling them ''interesting''.
She previously said: ''I thought, 'What a wonderful way to redo my song'. I mean, I recognised the chord changes. I thought it was... interesting.''
Other musicians have also weighed in on the debate with Noel Gallagher calling Gaga - who is currently on her 'Born This Way Ball' world tour - ''Madonna-lite''.
He said: ''I don't give a f***ing monkey's about Lady Gaga. It's all about the meat suit and the controversy. Is it about music? Really? She's got the publicity side sorted, but where's the f***ing music.
''Her album gets played a lot around my house by my daughter and it's Madonna-lite. Madonna was hardcore. She took it to The Edge musically as well as everything else.
''Twenty years from now, will we listen to Lady Gaga? No. She might think she is making a stand for the freaks and the weirdos. But they're not going to have any decent f***ing music to play are they?''