A real-life “spiderman” climbed four storeys of an apartment building in Paris to save a child who was dangling from a balcony.

In videos of the incident from Saturday afternoon, the child - a four-year-old boy, according to Le Parisien - is hanging onto the balcony while people watch in horror below.

After seeing the child was in danger, it took Mamoudou Gassama, 22, less than a minute to scale the outside of the building and haul the boy over the balcony to safety.

Gassama told Le Parisien he was watching a football match at a nearby restaurant with friends when he heard a commotion.

“We saw a lot of people screaming, honking, so, I crossed the road to save him,” he said.