Hiker stunned after realising Princess Catherine was climbing Scotland’s Ben Nevis alongside him

A Scottish mountaineer says he was speechless when he suddenly realised he was climbing up Ben Nevis — behind the Princess of Wales.

Jacky Leung told 7NEWS: “I could not really know what the proper names I should name her because I don’t want to be impolite.”

WATCH THE VIDEO ABOVE: Princess of Wales conquers Ben Nevis amid amateur hikers

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The Princess of Wales reached the top of Scotland’s highest mountain as she completed the Three Peaks Challenge, raising money for cancer research and support.

Leung said he spoke with the Princess, who asked whether he made it to the summit too.

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

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

“I was so happy. It was just mental.”

Leung described stormy conditions on the day of the royal climb, saying Her Royal Highness covered her face well with a cap so other climbers were unlikely to have recognised her.

He said there didn’t appear to be any bodyguards with her, but there were two camera operators.

“When she saw me, she tried her best to keep her smile, be very sincere, be very kind to me. It’s just so down to earth that experience,” Leung said.

The Princess posted a photo online showing her at the top of Ben Nevis.

“Cancer doesn’t just affect the body. It changes how you think and feel and profoundly affects every aspect of life,” she wrote.

“I know this personally, and that the journey through and beyond treatment requires more than medicine alone. I have taken on the National Three Peaks Challenge, not simply as a physical endeavour but as a chance to explore life beyond diagnosis and to give something back.

“The Royal Marsden is a place that holds great meaning for me and whose care and expertise are life changing for so many people.”