Leona Lewis says her trust has been betrayed by ''deplorable people'' over the years.

The 'Trouble' singer shot to fame in 2006 after winning the UK edition of 'The X Factor' and while she has had great success with her career, she admits she's encountered some nasty human beings along the way.

She told The Independent on Sunday newspaper: ''I've met some deplorable people over the past six years who have done some really bad things and I've seen their betrayal of my trust unfold before my eyes.

''It was hell but I've learnt from it and I'm much better at knowing who I should avoid.''

Leona also says she'll always be grateful to 'The X Factor' as it gave her the chance to become a star.

She said: ''I believe I could have had a career in the music industry without 'X Factor' but it was an amazing platform that propelled me to where I am now. I won't listen to anything against it.

''I got up every week and sang on stage without that lip-syncing that a lot of artists do these days - that takes a talent that you can't fake.''

She also paid tribute to her mentor and record label boss Simon Cowell, saying: ''He can be brash, he can be funny, but what doesn't come across is the sweetness.''