Maisie Williams arrives for the premiere of the final season of "Game of Thrones" at Radio City Music Hall in New York. Picture: Reuters

"Game of Thrones" star Maisie Williams says she had to wear a strap across her chest to reverse puberty while filming the fantasy series.

The actress, 22, has played Arya Stark in the series since she was 11 and explained that growing up on the HBO series has come with its own challenges, reports dailymail.co.uk.

The star told the US show "60 Minutes" that when she hit puberty she had to wear an uncomfortable strap to keep her chest flat whilst her character was "pretending to be a boy".

"I mean, there was a few seasons in the middle where I had to wear, like... like, a strap just to reverse puberty for the first few years while Arya was pretending to be a boy," she said.

But after a while, Williams, who has been on the show since its premiere in 2011, outgrew the garment and so producers gave her a "chubby belly" to even out her frame.

She added: "And then it got to the point where the strap was no longer working. So, I was about 15, right, and he gave me, like, this little, chubby belly. So it would, like, even out the playing field quite. 

"And then ... yeah, I was about 15 years old. Like, I kinda just want a boyfriend, honestly. I don't wanna wear this. This doesn't feel good."

Where to watch "Game of Thrones" 

Watch it on Mondays at 3am on  (repeat at 10pm) on M-Net, or straight after with the   DStv Now app  . 

You can also binge-watch all previous seasons of "Game of Thrones" on Showmax. Sign up for a 14-day free trial at Showmax.com