A new martial arts video in China reportedly teaches men how to make their crotch as hard as iron.

In the video, a monk named Shi Yanwu demonstrates Tiedang Gong - or ‘Iron Crotch Kung Fu’ - by having another monk kick him in the privates.

He is also shown with another monk hanging by a rope from his penis, and using his penis to pull a heavy stone roller.

The video claims that by practicing the martial art, “a man can not only protect himself better, but also improve his sexual agility and potency.”

The monk claims he learnt the technique at Shaolin temple, the Mecca of Kung Fu, but now is the last monk with this ability, reports Xinmin Net.

While denying any connection to the monk, the temple confirmed the existence of Tiedang Gong but insisted it was “to do with health not sex”.

(Ananova)