The couple were spotted together at London's M restaurant on Friday night following the actor's fight which was filmed for his upcoming TV show Idris Elba: Fighter.
She also shared a snap of herself lying on the floor with the actor, writing: 'I kicked his butt'.
The pair met for the first time back in 2015 after he DJ'd for her Rebel Heart tour. Opening up about meeting her while promoting Luther, the actor said: 'I was excited, I had a great time. Madonna is a legend. I got there, I met a beautiful person that has been working for ever and ever, amen, and is still going.'
However on Monday, Idris responded to the rumours by posting this tweet:
Am I sleeping with Madonna? No motherfuckers... "Don't believe the Hype".— Idris Elba (@idriselba) 31 October 2016