Charles fulfils his promise to the shelter

The prince is offering 500 prints of a watercolour he painted of the Annapurna Himalayan mountain range for £150 each.

The proceeds will go to the Maiti hostel in Kathmandu, which aims to stem the flow of child prostitution in the region.

"An angel of mercy"

The prince visited the hostel in February, and spent some time chatting to the girls who live there, of whom 90% are HIV positive or have sexually transmitted diseases.

After hearing their stories, the prince described the organiser, Anuradha Koirala, as "an angel of mercy" and promised he would keep in touch with the project.

Child prostitution

The girls in the hostel are just a small number of the thousands of Nepalese children lured from their homes every year with promises of jobs or marriage.

Most end up working in brothels across the border in India.

Human rights groups estimate that nearly 200,000 Nepalese girls have been forced into prostitution in India, many in the city of Bombay.

Promoting his cause

This is not the first time the prince has sold reproductions of his work for charity, but he has never before used a tabloid newspaper for the purpose.

Anuradha Koirala tells of her delight at the prince's gesture

The newspaper has also printed a letter from Charles telling of child trafficking and prostitution and the "selfless dedication and sacrifice" of the hostel's head, who, he says, is "living under constant threat of retribution."

The prince's painting

Speaking to BBC Radio 5 Live's Breakfast Programme, Anuradha Koirala, an ex-school teacher, said: "I was filled with joy. We are very much thankful to his majesty for thinking about the girls.

"I spoke to the children and they were really, really very happy."

In a touching moment, she then asked the programme to give her Prince Charles's address so the hostel can write to thank him personally.