AFTER spending her student nights running over the roofs of Oxford, an academic has turned her youthful escapades into an award-winning children’s novel.

Katherine Rundell, a fellow at All Souls College, has won the £5,000 Waterstones Children’s Book Prize for her novel Rooftoppers.

She said: “This is absolutely amazing, it will help so much.

“I’m in shock. I can’t believe it.

“I was convinced I hadn’t won – the other entries were so good.”

Her second book, it tells of shipwrecked Sophie as she searches Paris for her mother with help from the rooftoppers – urchins who live on the roofs of the city.

Ms Rundell, 26, admitted that Oxford was a source of inspiration for the story as she used to spend her evenings as an undergraduate at St Catherine’s trespassing on the rooftops of New College.

She said: “You feel like a living gargoyle. It’s wonderful.”

Rooftoppers, which was also named the best book in the 5-12 age group category, beat teen category winner Geek Girl by Holly Smale and Nicola O’Byrne’s picture book Open Very Carefully to the main prize.

Both runners-up received a cheque for £2,000 in a ceremony at Waterstones store in Piccadilly, central London.

Melissa Cox, children’s new titles buyer for Waterstones, said: “Katherine Rundell’s Rooftoppers is a hugely deserving winner of the 10th Children’s Book Prize – it already feels like a classic.

“Her lyrical writing style is immediately charming, effortlessly taking the reader on magical flights of fancy over the English Channel and up on to the rooftops of Paris.’’ The three finalists will see their sales boosted by a promotion campaign in more than 278 Waterstones shops nationwide.

The firm’s managing director James Daunt said: “The 2014 category winners are each of an outstanding quality which our booksellers have delighted in unearthing and passionately championing.”

Ms Rundell is a supporter of the Oxford Mail’s Reading Campaign, to give children targeted help to improve reading skills.

She said: “Books change your life. They kick down doors and roll out red carpets like nothing else can.

“I salute anything that improves children’s literacy.”