Mariah Carey on 'the loo' when writing 'Hero'

Mariah Carey was in "the loo" when she was inspired to write 'Hero'.

The singer has revealed the idea for her hit track came to her while she was using the bathroom.

Mariah, 38, said: "Sometimes I wake up and in the middle of the night and have an idea and have to get up and record it straight away before I forget it.

"Or with 'Hero', I was in the studio and someone was telling me about this film 'Hero' with Dustin Hoffman in it. I took a walk to the loo and when I came back I had this idea for a song, and that was what then became 'Hero'."

Mariah - who appeared on UK TV talent show 'The X Factor' last weekend - also revealed she still finds it hard to control her nerves when she is performing live.

She added to British TV series 'This Morning': "I really used to get very nervous and I would have to try so hard to stay calm before shows, but it's hard. I come from a studio background and I had to learn doing it live in front of the world. On shows like 'American Idol' at least they get training to sing live."