Sam Claflin was left with seriously smelly socks on the set of Me Before You after Emilia Clarke played a fishy prank on her co-star.

The Game of Thrones actress reveals she used the remains of a seafood lunch they had been served to get Sam back after engaging in a merciless practical joke war while shooting the romantic drama, about a young female caretaker who falls for her quadriplegic patient.

"I put fish in his socks, but that was just one of them," Emilia smiled to Eonline.com. "(It was) the fish that we had for lunch. I had limited resources. He had just pranked me and I was like, 'I've got 20 minutes until the end of the day so I have to get this done.'"

She also left Sam red-faced by fitting his character's wheelchair with a fart machine, but The Hunger Games star had a few tricks up his own sleeve too - he once jumped out of Emilia's trailer closet, terrifying her with his shocking exit from the wardrobe.

However, the fun-loving pair found themselves in a little unexpected trouble during a break from filming, when they decided to take a walk through a field near London - and ended up being chased down by a herd of cows.

Sam laughed, "We ran and I carried Emilia on my back!"

The British actress is known for being somewhat of a prankster, and, in recently-released footage from behind the scenes of Game of Thrones, she was caught drizzling caramel fudge all over her sleeping co-star Joseph Naufahu, after he dozed off in between takes for her fiery nude scene in the current season six of the fantasy drama.