Rugby World Cup 2019: Springboks halfback Faf de Klerk 'massively surprised' by reaction to South African-coloured speedos

Springboks halfback Faf de Klerk admits he's surprised by the reaction to the South African-flag underwear he wore during the Rugby World Cup celebrations.

De Klerk made international headlines, when he met Prince Harry, after the Yokohama final, wearing nothing but his colourful speedos.

The 28-year-old also wore them when posing for victory photos with the Webb Ellis Cup, after South Africa beat England 32-12 in the decider earlier this month.

Speaking to South African publication Sport24, de Klerk said he did not expect the response, but was happy that people were able to make light of it.

"I was massively surprised," he said. "I didn't do it intentionally, but the response has been great.

"It's created a nice vibe and the people are enjoying it, so I'm all for that. It's all for fun."

De Klerk added there wasn't anything special about the speedos, saying other Boks players also wore them during test matches. 

"There is no massive backstory. I just always play in a South African speedo when I play for the Springboks. 

"I've probably played the last two years with it." 

Two weeks after the World Cup ended, de Klerk is still rocking his famous undies. 

As part of a promotion with Cipla South Africa, de Klerk has challenged other men to improve their personal "ball skills", when checking for signs of testicular cancer.  

"Don't Faf this one up! Be ballsy enough to check your balls," he wrote on Instagram, along with a photo in his South Africa-coloured speedos. 

"Testicular cancer is curable if caught and treated in the very early stages! Check out www.fafchallenge.com for some important tips and tricks on how to up your ball skills.

"I'm now challenging Siya [Kolisi], Jesse [Kriel], and ALL OF YOU to get into your speedo, post a pic to help spread the word on this important cause."