Richard E. Grant says he left his 'bloodied' underwear in his room at Sandringham House while staying with King Charles

• In his memoir, Richard E. Grant recalls leaving his bloody underwear in his Sandringham House room.
• The "Loki" and "Withnail and I" actor stayed in 2001 with then-Prince Charles and his wife, Camilla.

The Academy Award-nominated actor Richard E. Grant says he once left "bloodied" underwear in his room at Sandringham House when he and his wife, Joan Washington, were invited to stay with then-Prince Charles and his wife, Camilla, then the Duchess of Cornwall.

Grant recalls the moment in his new memoir, "A Pocketful of Happiness," which was released in the US on Tuesday. The book offers readers a look at the actor's life and career and provides an emotional insight into Washington's lung-cancer diagnosis and her death in 2021.

Grant writes that he and his wife stayed with the royals in 2001 shortly after he had returned from horse training for his role as Sir Hudson Lowe in "Monsieur N.," a 2003 film about Napoleon Bonaparte.

He adds that he had been "clinging on for dear life" for several days while training because the horse he was riding was "so feisty."

"When I changed for dinner, Joan announced, 'Your bum's on fire.' It was indeed," the actor writes of visiting the royals at Sandringham. "Bloody whiplashes across each cheek! All our clothes had been unpacked, hung up, suitcases removed, and outfits laid out for the evening, so had nowhere to dispose of my bloodied boxers."

To hide the evidence, Grant writes, he decided to put them out of sight "on top of the high wardrobe."

He says: "I flung the bloodstained shorts up there, convinced they would never be found. Then wrapped voluminous amounts of loo roll around my bahookie, to avoid the risk of staining any Sandringham sofas or cushions."

Grant adds that he and his wife forgot about the bloody underwear until the next day when they went back to their room and found that the boxers had been cleaned.

The 66-year-old star writes: "Completely forgot about them, until it came time to change for dinner the following evening. Went upstairs to our bedroom, and there they were. Freshly laundered, de-stained, and immaculately pressed, on the bed alongside my black-tie suit."

While Grant was incredibly embarrassed by the situation, his wife found it hilarious, he writes.

The actor says: "She instantly re-enacted how she'd imagined the guilty pants were discovered, hoisted with a pole from atop the cupboard, and removed with great ceremony to the laundry, where the household staff would have been regaled with tales of the actor who clearly favored heavy-duty S&M conjugals under a royal roof!"

The "Loki" actor also writes that the incident still haunts him.

"Joan then took great delight in telling all the other houseguests what had happened and, whenever our paths have crossed in the intervening years, that's all they've talked to me about," Grant writes.

Later in the book, Grant details how Charles and Camilla visited Washington after she was diagnosed with cancer. It's not clear whether they knew about the bloody underwear.