Leona Lewis has made a film exposing child labour and cruelty to animals.

Leona Lewis

Leona Lewis

The 30-year-old singer has narrated a clip created by PETA (People for the Ethical Treatment of Animals) which claims to expose Bangladesh's billion-dollar leather industry.

In the disturbing video, cows are seen being transported in severely crowded conditions and getting their throats cut with a knife, while goats are also seen being butchered.

The animals are skinned to make shoes, belts, jackets, handbags and other products that are exported around the world.

PETA claims tanneries use toxic chemicals to stop animals' skins from decaying and unprotected workers, including children, soak hides in chemicals while standing barefoot.

Some workers are said to have lost fingers through operating the dangerous machinery required to do the job.

In the clip, Leona says: "The production of leather hurts animals, workers and the environment.

"Please consider the impact that your purchases have, and buy only cruelty-free synthetic, natural fibre and other vegan clothing and accessories."

Several other big names including Pink, Joaquin Phoenix, Charlize Theron, Joss Stone and Natalie Imbruglia have also teamed up with PETA for similar campaigns.

The organisation's motto is: "Animals are not ours to wear".