Emeli Sande has revealed her school friends once stole a song she had written to start their own band.

The 24-year-old singer-songwriter has been named by Simon Cowell as his favourite songwriter and has written for Leona Lewis, Cheryl Cole, Cher Lloyd, Susan Boyle and Tinie Tempah. She began writing when she was seven and was shocked when one of her own songs was used when she was still at school.

Emeli revealed: "It was about an alien coming to earth looking for love, and it wasn't very good. It didn't have much structure.

"My friends formed a girl group for this talent show and they sang my song. I was in the audience and thought, 'I recognise that!' That was my first lesson in copyrighting, anyway.

"The crowd seemed to like it, and they had a dance routine and everything. It was flattering I suppose, and we're all still friends now, so I like to tease them about that."

But now the Heaven singer enjoys hearing other people singing her songs.

She said: "I don't 'sell' songs, as such. I give them to people. I love the reinterpretation, and the fact someone can change a lyric to mean something I'd never thought about or intended.

"The first time I heard someone singing a song of mine was Cheryl Cole, who sang Boys. Leona Lewis did another around that time, too.

"Some people think it might be odd writing for other people, but I haven't felt like that. There's no one who's sung a song of mine that I haven't respected, and no one who made me think they didn't understand what the song was about."

:: Emeli Sande's debut album Our Version Of Events is out now.