One of the great World Cup success stories has been the "magic spray" used by referees to keep a defensive wall 10 yards (9.15 meters) from the ball at free kicks but its inventor says he is more concerned with the good of the game than making millions of dollars.

Heine Allemagne, 43, who has given FIFA free use of his invention at the finals, says he is driven by a love of the game and helping referees keep discipline rather than becoming a multi-millionaire.

His invention could hardly be more simple. The referee sprays a line of biodegradable foam ­derived from vegetable oil in a line on the pitch ­indicating where the players must stand at a free kick, and that line disappears within a minute or two.

"I had no commercial ambition, I wanted to develop the product. Perhaps there will be some financial side but that can come later, I wanted to get the product perfect for football.

"I wanted to help the referees keep discipline. The time now taken at free kick has dropped from 48 seconds to around 20 seconds. There are less yellow and red cards and more goals from free kicks, and the players respect the line."

Although the spray cans are not yet widely available, Allemagne said the retail price would be around $5. FIFA took delivery of 320 cans for the 64 World Cup matches and the Brazilian has absorbed the hypothetical cost of $1,600 himself.

One of the more intriguing aspects of his story is the time it took for such a simple concept to become accepted.

Although local soccer authorities welcomed it in the early stages he said FIFA President Sepp Blatter and Secretary General Jerome Valcke needed some convincing when they reached a more advanced stage.

"Some people needed convincing like them. Blatter was skeptical in the beginning but then realized this solved a football problem.

"Some people did not think it was necessary or would act as enough deterrent to keep people behind the line. But they changed their minds."

Allemagne, who was born and raised in the state of Minas Gerais, was working in TV and graphic design when he came up with idea 14 years ago.

A keen amateur soccer player, he was increasingly irritated by the time-wasting that surrounded every free kick at every level of the game with players encroaching towards the ball.

The prototype was first used in the minor Copa Belo Horizonte in 2000.

It was gradually used in higher levels and two years later the Brazilian soccer governing body CBF sanctioned its use after it received a 100 percent ­approval rating by the referees who had it.

In 2006 Allemagne joined forces with Argentinean Pablo Silva who was independently working on a similar product and since then they been working together on the spray they called the 9.15 Fair Play spray - the metric distance players need to be from the ball at free kicks.

By 2012 the spray, with many technical modifications along the way, had been tested in 18,000 professional games and was authorized by the ­International Football Association Board who ­approved its use at all levels in 2012.

FIFA tested it at the Under-17 and Under-20 World Championships in 2013 and it was also used at the Club World Cup before being used for the first time at the World Cup.

Although he holds an international patent for the product and is protective of it and could become a very wealthy man out of it, that does not appear to be his goal.