A painfully thin British ­teenage girl poses in a secret dance show under the noses of Nazi occupiers.

Less than 10 years later, this brave would-be ballerina – Audrey Hepburn – was winning an Oscar alongside Gregory Peck in the hit movie Roman Holiday.

Audrey went on to become one of Hollywood’s most iconic actresses with a string of classics including Breakfast At Tiffany’s and My Fair Lady.

But she turned her back on Tinseltown and spent the last third of her life working tirelessly for the United Nations charity Unicef, touring war-torn poverty-stricken regions.

And now, 22 years after her death at the age of 63, a new exhibition of rare and unseen pictures helps to explain why one of the most beautiful actresses of the 20th century spent so much time raising the plight of orphans and refugees, the Sunday People reports.

The snaps also highlight the incredible bravery that young Audrey showed in helping Dutch resistance fighters in the Second World War.

Her divorced dad, a London banker, had sent his 10-year-old daughter to live with her mum, a Dutch baroness, at the outbreak of war in 1939 because Holland was ­expected to stay neutral.

But the following year the Germans invaded and Audrey was trapped. She lived in fear of being kidnapped and taken to a military brothel along with other girls.

Her mum sent her to ballet classes in their home town Arnhem and the pupils began giving ­secret dance shows to raise money for the resistance.

Performances were staged in ­houses behind closed curtains while Nazi patrols roamed outside. To avoid ­being discovered, ­audiences never clapped.

Later the movie icon, who enthralled millions, said: “The best audience I ever had made not a single sound at the end of my performance.”

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Audrey and the ­other performers then risked their lives by ­taking money and ­messages stuffed in their shoes to ­resistance contacts.

By the winter of 1944, with the Allies’ “Bridge Too Far” operation to liberate the region ending in disaster, Audrey was starving along with the rest of Holland.

The Germans had halted food imports in retaliation for resistance attacks. Audrey told later how she ate

She survived – unlike 20,000 other Dutch citizens – but by the end of the war weighed just over six stone even though she was 5ft 10ins tall.

Her eldest son from her first marriage, Sean Ferrer, 54, says: “That experience shaped her whole life. It made her ­appreciate the freedoms that most people take for granted.

“It made her oppose any form of ­extreme government. It also turned her against Germany. She wouldn’t have anything German in the house.

“On the other hand, she was ­grateful to the people who liberated her. She never forgot the chocolates and the outstretched hands – the little acts of kindness to children like herself.

“Later in life, those memories inspired her to work for Unicef. She wanted to give something back to the world.”

Audrey’s still-skinny figure and pixie hairstyle were at odds with the fashion for big-boobed, blonde bombshells who were leading ladies during the 1950s when she took Tinseltown by storm.

And even Audrey herself could not ­understand why people thought she was attractive.

Her son from her ­second marriage, Luca Dotti, 45, says: “She thought she had a big nose and big feet, and she was too skinny and not enough breast.

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“She would look in the mirror and say, ‘I don’t understand why people see me as beautiful’.”

But the new exhibition at London’s National Portrait Gallery reveals the actress was loved by the camera even then.

One of the unseen pictures shows her as a nine-year-old and in another Audrey walks her dog through Richmond Park in 1950, just as she is about to hit the big time.

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Luca, who has helped put together the Portraits Of An Icon show, said his mum wasn’t worried about her looks fading.

He said: “She was actually very happy about growing older because it meant more time for herself, more time for her family, and separation from the frenzy of youth and beauty that is Hollywood.”

Luca added: “She would be honoured to have an exhibition dedicated to her at the National Portrait Gallery – and glad to be back home.”