The Prince and Princess of Wales have released touching photos of Kate being warmly hugged by her family at the end of her marathon 24-hour mountain trek.

The princess revealed a week ago that she had just finished the gruelling Three Peaks Challenge, in a surprise feat of endurance to raise money for a cancer charity and “explore life beyond diagnosis”.

The future queen climbed the highest mountains in Scotland, England and Wales – Ben Nevis, Scafell Pike and Snowdon – within 24 hours, starting on the night of June 27. She trekked for a total of 37 kilometres, climbing a total of 3064 metres and travelled more than 740 kilometres by road between the locations to complete the challenge.

Numerous videos and images have already been shared online by surprised hikers who met the princess during her climb. They include Scottish mountaineer Jacky Leung, who said he was speechless when he met Kate as he was climbing up Ben Nevis.

“I could not really know what the proper names I should name her because I don’t want to be impolite,” he said.

Leung eventually spoke to the princess, who asked if he’d also made it to the summit.

“I said yes, we were very lucky to get to the top. And then she said, well done to me,” he said.

“I said to her, ‘you were so inspiring’ and then she said ‘thank you”.

“I was so happy. It was just mental.”

On Sunday (British time), images of Kate being met by husband Prince William and their children Prince George, Princess Charlotte and Prince Louis, as well as her parents Carole and Michael Middleton and brother James Middleton, were released on Instagram.

They show the princess hugging her husband in one image, with her arms around 11-year-old Charlotte in another.

She is also seen with her arm around 12-year-old George, holding hands with Louis, 8, and chatting to her family.

The final group picture shows Kate with her family, including her parents, brother, and his dog.

“This time last week, completing the National Three Peaks Challenge,” the caption says.

“A huge thank you to everybody who has supported The Royal Marsden Cancer Charity.”

Kate’s brother James Middleton also posted a photo of the two of them hugging on his Instagram, saying he was “so incredibly proud of my darling sister”.

“Two years ago, I told you we’d climb this mountain together,” Middleton wrote.

“We talked about climbing mountains while you were in hospital, and about the incredible healing power that nature can have for both the body and the mind.

“So it was such an honour to join you for your Three Peaks Challenge for the Royal Marsden Cancer Charity.

“Seeing how far you’ve come is nothing short of inspiring. Your strength, resilience, and determination, all while being the most amazing mother, wife, daughter, and sister, inspire me and so many others every single day.

“Keep being exactly who you are.”

Kensington Palace said it believed the expedition was a royal first, with the princess being the first member of the royal family to complete the Three Peaks challenge.

-with AAP