JK Rowling has revealed she’s constantly losing things and is still devastated after misplacing her mother’s engagement ring.

“I lose things constantly. It’s one of the things that irritates me most about myself. The worst thing I ever lost was my mother’s engagement ring,” the Harry Potter author told HELLO! magazine.

Losing things is a big theme in Rowling’s new children’s book, Christmas Pig, which she says was inspired by her son’s beloved stuffed pig.

“My son David’s favourite, can’t-go-to-bed-without-him toy when he was little was a pig just like the one in the story, made of soft towelling material and filled with belly beans. Although the real-life toy isn’t called Dur Pig. That’s my invention,” she said.

“David was prone to hiding his pig in all kinds of places, so bedtime was sometimes put off while he tried to track the pig down.

She continued: “At one point, I was so worried that David was going to lose his pig for good that I bought a duplicate just in case. One day, while poking around in a cupboard, three-year-old David found the replacement, declared him to be his original pig’s brother and kept him too, so they’re both with us.”