By Hugh Schofield In Paris

David Belle, acrobatic star of the BBC's new advertising campaign, is the acknowledged guru of a new urban sport in France known as Le Parkour - or obstacle-coursing.

Described by adepts as an art-form or even a philosophy, Le Parkour consists of finding new and often dangerous ways through the city landscape - scaling walls, roof-running and leaping from building to building.

"Le Parkour - or the Art of Movement - is a way of using the obstacles found in one's path to perform jumps and acrobatics.

Belle: Aims "to make people understand what it is to move"

"Everything must combine speed, fluidity, aesthetics and originality," reads one of several websites dedicated to the sport.

Belle, 28, is credited with having invented Le Parkour as a teenager in the Paris suburbs, along with his friend Sebastien Foucan. Today he is universally recognised as its leading exponent.

The two boys led a gang known as the Yamakasi, who became famous last year when they starred in a film of the same name by director Luc Besson, of Fifth Element fame.

The film is about a group of "Parkouristes" who feel responsible when an inexperienced fan is injured in a fall and set about a spectacular series of robberies to raise money for his operation.

'Need to exist'

The blurb described the Yamakasi as "modern-day Samurai," but by this point Belle had left the group, fearing that the commercialisation was threatening the inner spirit of the sport.

He is now the leader of a new group - Les Traceurs - based in the Paris suburb of Lisses.

"We do it because we feel a need to move, we feel a need to exist - to show that we are there," he said in a television interview last year.

"Our aim is to take our art to the world and make people understand what it is to move."

Beginners are advised not to start with high walls

Beginners are advised to practise daily, not to start with high walls, to work in groups and above all not to be dared to go too far.

"Teasing doesn't kill - a bad jump can," warns Ombre (Shadow), a 17-year-old Parkouriste from La Louviere outside Paris.

There are a series of basic moves, from the cat-jump - in which the exponent places two hands on an obstacle and then leaps between them - to the tic-tac, which is a kind-off push-off taken in mid-movement from a wall or other surface.

Apart from Belle's Traceurs and the Yamakasi, there are several other gangs in France, with names like the Wakazai, the Ninjas, Impala and Parkour Clan.

Fans say Le Parkour has many of the qualities of an eastern philosophy, encouraging discipline, self-improvement and interdependence.

For sociologists, Belle and his followers demonstrate the classic human urge for freedom within the clogging world of modern suburbia.

As Belle himself puts it: "We want to go where no human has ever been before."