A report from international Christian charity, World Vision, has revealed the terrible price paid by some of the world's most vulnerable children to put beauty products, often labelled as 'cruelty-free', on the shelves of retailers and bathrooms across the world.

In the report, titled 'The High Price of Beauty', World Vision examines the convoluted supply chains involved in delivering mined and agricultural products that make up around 30 per cent of the ingredients in cosmetics, with the demand for agricultural products rising due to the growth of the natural beauty industry.

World Vision said that this often involves the use of child labourers, either working to support their families, or the victims of trafficking.

"Research shows that there are six commonly used ingredients that are at risk of using child labour: palm oil, cocoa, vanilla, shea, mica, copper," World Vision said.

"Instead of going to school, many children help grow, harvest, mine and transport these ingredients. They work in dangerous places at risk of injury, heatstroke, diseases and even death. And sometimes for as little as $2 a day."

It is calling on companies and governments to take steps to save the 140 million children it estimates will still be victims of child labour by 2025.

"The shocking reality is that vulnerable children in deprived areas of the world are working in dangerous, illegal mines to dig for minerals for cosmetics, causing huge suffering and even resulting in deaths," Mark Sheard, the CEO of World Vision UK, said.

"It's a shared responsibility ... We should not turn a blind eye to the reality of where some of their ingredients have come from, as this will not erase the consequences – brands must be held accountable."

World Vision's investigation into the policies of major beauty companies found that some progress has been made. However, it also found massive increases in children working to gather ingredients used in cosmetics, such as cocoa.

"Improved supply chain legislation has helped improve the practices of companies on paper in recent years, but we're still waiting to see that translate into change that can ultimately help eliminate child exploitation ... we believe that every child has a right to a happy and fulfilling childhood," Mr Sheard said.