A runner came last in his 400-metre race as his penis kept falling out of his shorts.

Alberto Nonino lost a race as his penis kept falling out of his shorts

Alberto Nonino lost a race as his penis kept falling out of his shorts

Italian decathlete Alberto Nonino suffered the disastrous wardrobe malfunction as he competed at the World Athletics U20 Championships in Colombia.

Nonino, 18, had made a strong start to the race but he was filmed grabbing his crotch several times on the final straight as he ended up at the back of the pack.

Sports reporter David Sanchez de Castro revealed the details about Nonino's cock-up after the footage went viral.

He wrote: "The Italian Alberto Nonino in lane five begins very well but crosses the finishing line last. He had his penis out, literally.

"His penis escaped the side of his shorts and he had to hold it because it wasn't allowing him to run properly, which is normal when your dongle is swinging from side to side."

Nonino later admitted that his poor performance in the event was due to his decision to race without underwear.