Katy Perry had a particularly emotional response to a contestant on the latest episode of hit US reality series American Idol.

The “Roar” singer has served as a judge on the show since 2018.

Last night’s 14 February episode saw hopeful singer DJ Johnson, 18, perform a self-written composition called “Scars”.

Before singing, she shared the backstory of her life and upbringing, including her troubled relationship with her mother, who left the family when Johnson was a child.

At one point during the performance, Johnson had to stop singing, and required support from her father before she was able to continue.

After finishing the song, however, Johnson impressed the judges, including Perry, who was moved to tears by the act.

It’s about if you can take that pain and turn it into a purpose. You give hope to so many people,” she added.

American Idol airs in the US on Fox. Some old episodes can be streamed in the UK on Netflix.