SA rugby stars strip down for cancer campaign

South Africa's Rugby World Cup heroes are stripping down to their underwear to raise awareness about testicular cancer.

It is a challenge thrown to them by teammate Faf de Klerk, famous for celebrating the world cup win against England while only dressed in his underwear.

De Klerk took to Twitter with his #FafChallenge, a campaign to get men "ballsy enough to check on their crown jewels" for signs of testicular cancer.

The challenge is a partnership with Cipla South Africa, a pharmaceutical company, which runs a website that offers guidelines on how to self-examine unusual lumps in testicles, and a fact sheet on testicular cancer.

A spokesperson for the company is quoted by the News24 website as saying that "they were hoping for the same talkability about these important self-checks that women had established about regular breast checks".

The campaign has team captain, Siya Kolisi, and other teammates joining including Makazole Mapimpi, Cheslin Kolbe, Damien de Allende, Malcolm Marx, and Jesse Kriel.