Murs was in the middle of a style fitting when he was told he had to evacuate the building after a fight between two kitchen staff resulted in two people being stabbed.
The pop star, who rose to fame on the X Factor in 2009, recalled the dramatic day when he explained: “I was there – with my pants down.
“I was doing a styling fitting so I was getting changed and trying to put clothes on then we heard this big kerfuffle and a lot of noise,” he added to The Sun.
“The whole place got evacuated. To walk past the canteen, to see what had happened — there was a lot of blood and two guys involved in a fight.”
“I put my trousers on, I put my suit on – I looked like MC Hammer, I had these massive trousers on – but listen, it was dealt with the right way.”
“The most important thing is no one died, the people have been arrested and they will get dealt with,” he continued to comment.
Murs had previously been caught up in a frightening incident in central London last year.
Taking to Twitter to tell his followers what was happening, Murs posted: “‘F***, everyone get out of Selfridges now. Gun shots!”
He went on to add: “Really not sure what’s happened! I’m in the back office… but people screaming and running towards exits!”
However, he later added that no gunshots had been fired in the iconic store.
“Being told no shots in Selfridges! Have no idea the whole store went crazy!,” he told his fans and followers.
It was later revealed that an altercation between two men in Oxford Circus tube station caused the frenzy and that no shots had been fired.