The 'Domino' singer explained how she had to get helped out by Jay-Z's entourage at the pair's recent London gig.
"I went with will.i.am to the first [Jay-Z and Kanye West] 'Watch The Throne' show in London," she is quoted as saying in The Sun.
"I somehow managed to find myself walking into the stage with them all - will, Kanye, Jay-Z, Kim Kardashian. I was like, 'Wow, what a crew', then me and my friend got stuck in the toilet.
"We nipped in to do our make-up and my friend knew the door was broken but locked it anyway and said, 'Babe I think I've broken the door'.
"They'd been on for one song, we could hear them and it got to about 15 minutes and Jay's security came in and they literally kicked down the whole door."
Jessie J performed yesterday at BBC Radio 1's Hackney Weekend event alongside the likes of Plan B and Rihanna.
Watch the video for Jessie J's 'Who You Are' below: