Rosie Huntington-Whiteley was left heartbroken on her charity trip to Africa with UNICEF.

Rosie Huntington-Whiteley

Rosie Huntington-Whiteley

The 29-year-old British supermodel travelled to Lesotho in southern Africa with UNICEF UK to meet families and children affected by the food and water crisis in the region.

Rosie was shocked to see the poor standard of living conditions and stunned to learn that many women and young girls have been forced to trade sex for food.

In an essay on her trip for VOGUE, the former Victoria's Secret star wrote: "UNICEF told me that in some cases women and girls are having to resort to exchanging sex for food. The thought of a young girl having to go to such extreme measures just to survive is just heartbreaking."

Rosie - who has started to make a move into film having starred in 'Mad Max: Fury Road' and 'Transformers: Dark of the Moon' - has made a plea for support of the charity to help save the lives of the people in the region.

She said: "It is so important that we make sure these families are not forgotten at a time when they so desperately need our help. I'm urging everyone to do all we can to help UNICEF deliver the life-saving food, medicine, clean water and support that these children so desperately need."

The drought has prompted the government in Lesotho to declare a state of emergency, with more than 530,000 people estimated to be affected.