London, England (CNN) -- A Paralympic gold medal winner will not be allowed to compete in the Beijing Olympics later this year after athletics' governing body ruled that his specially-designed prosthetic limbs gave him an unfair advantage over other runners.

The International Association of Athletics Federations ruled that Oscar Pistorius' shock-absorbing carbon-fiber prosthetics gave him a "demonstrable mechanical advantage" compared to able-bodied athletes.

Pistorius, nicknamed the "Blade Runner" because of his prosthetics, won gold in the 200 meters and a bronze medal in the 100m at the 2004 Paralympic Games in Athens.

The 21-year-old South African, who lost his legs when he was a baby, has since competed in two able-bodied races in which he finished second and last.

In November, the IAAF carried tests on Pistorius over two days at the German Sport University in Cologne to determine if his prosthetic limbs, known as "cheetah" prosthetics, could be considered a technical aid.

A team of more than 10 scientists used high speed cameras, special equipment to measure ground reaction forces and a three-dimensional scanner to record body mass.

The IAAF determined that Pistorius was able to run "with about 25 per cent less energy expenditure" than other sprinters, it said in a statement released on its Web site Monday.

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