The moment Rio paramedics dropped an Olympic French athlete who suffered a horrific leg break during his event while loading him into an ambulance has been captured on video.

A female onlooker clasps her hands to her mouth and looks visibly shaken as the stretcher slips from medics’ hands.

The injury occurred while Samir Ait Said was on the vault during the qualification round in the men’s gymnastics.

The snapping sound could clearly be heard around the stadium and by viewers watching on television.

He landed badly and his left leg folded beneath him, before swinging loosely below the knee as he fell to the floor.

The 26-year-old Olympian missed the London 2012 games after fracturing his leg in three places during the European Championships.

French team leader Corrine Moustard-Callon, commended his commitment and said doctors are investigating the extent of the damage.

She said: "It is very difficult for the team. He was one of the friendliest on the team which is very difficult - he came to win a medal and gave everything 200 per cent.

(EPA (EPA)

"He is in the hospital with a doctor now.

"We don't know what happened, except that it was his tibia. We will do more exams to see if it just the bone."

The gymnast stoically acknowledged the crowd’s support with a hand wave after suffering the injury before being carried away.

The incident unfolded on an eventful second day at the games.

British Adam Peaty broke his own 100 metres breaststroke world record in the heats and is hotly-tipped to become our first male Olympic champion in swimming since Adrian Moorhouse in 1988.

Other highlights on Saturday included Yusra Mardini, the 18-year-old who is representing the Refugee Olympic team who won her 100m butterfly heat to huge cheers from the crowd.

Mardini escaped the Syrian war one year ago. She was hailed a hero after pulling a boat full of 20 people for three-and-half hours after its motor failed while trying to reach Greece from Turkey. She could barely stand when it reached Lesbos.