Game of Thrones: Nikolaj Coster-Waldau's prank almost backfired spectacularly

Game of Thrones star Nikolaj Coster-Waldau has opened up about a prank he pulled that almost got him sued. Photo / AP.

Game of Thrones star Nikolaj Coster-Waldau's has opened up about a prank he pulled that didn't go down well with the bosses of the HBO fantasy drama series.

The Danish actor, who plays Jaime Lannister on Game of Thrones, told Digital Spy about the hilarious stunt he pulled a few years ago that almost got him sued.

"There'd been a lot of talk about Jaime's hair in the early seasons — his long golden locks," Coster-Waldau said. "Once he lost his hand, I thought he should maybe have a haircut. And then I thought, 'Why don't I just pretend?'

"This is five, six seasons ago — I sent them an old picture where I had a buzz cut. I sent a long letter where I explained I'd taken control of my character, and I want to be respected. I said that my integrity as an artist was at stake!"

The actor didn't hear anything back and forgot about the prank. But when he landed in Northern Island to start filming again he received a panicked call from one of the Game of Thrones bosses who had been freaking out behind the scenes.

"I was in the car from the airport. The first AD (assistant director) said, 'Do you have any hair?' Then he explained how poor Kevin — who is the head of hair — had been frantically trying to build a wig with what he had, which wasn't a lot," Coster-Waldau said.

"I said, 'It's just a joke! Did you really believe?' They all believed it. They'd also called my manager. HBO had started to talk about suing me and it had gotten out of control."

The eighth and final season of Game of Thrones returns on Monday April 15.