(CNN) -- A double amputee sprinter has won the right to be eligible to compete at this summer's Olympic Games in Beijing after sport's highest court backed his appeal against a ban imposed by athletics authorities.
Paralympic champion Oscar Pistorious competed in two able-bodied athletics meetings in 2007.
The Court of Arbitration for Sport ruled that South African Oscar Pistorius, who runs on prosthetic blades, is eligible to compete against able-bodied athletes.
Pistorius, 21, who lost both legs below the knees when he was a baby, runs on shock-absorbing carbon-fiber prosthetics that resemble bent skis -- earning him the nickname "Blade Runner."
Pistorius, a Paralympic Games champion and world record holder, had lobbied the International Association of Athletics Federations (IAAF) to allow him to compete at the Olympics this August, but after extensive tests the IAAF ruled in January that his J-shaped prosthetics qualify as technical aids, which are banned in IAAF-governed sports.
The IAAF does allow athletes with prosthetics to compete in able-bodied sports, as long as the IAAF believes they do not give the athlete an unfair edge.
But Friday's ruling by the CAS in Lausanne, Switzerland, overturned that verdict. In a statement, it said that its panel had "not been persuaded that there was sufficient evidence of any metabolic advantage in favor of a double-amputee" using Pistorius' blades.
Appeals of court decisions are allowed, but on very limited grounds. But the CAS said it did not exclude the possibility that future scientific tests could be developed which might enable the IAAF to prove that the blades provided Pistorius with an advantage over able-bodied athletes.
The South African won gold in the 200 meters, and bronze in the 100 meters at the 2004 Paralympic Games in Athens. He holds the Paralympic world records in the 100, 200, and 400 meters.
Since Athens, he has competed in two able-bodied races in which he finished second and last, respectively.
Pistorius will have emphasized to the court the disadvantages he feels he has by running with prosthetics, CNN World Sport's Don Riddell said.
"There are disadvantages when it's windy, when it's raining, (and) it takes him longer to get up to speed at the start," Riddell said. "He will be hoping that they take everything into consideration and not just rule on how much spring his prosthetic limbs give him."
In November, the IAAF carried out tests on Pistorius over two days at the German Sport University in Cologne to determine if his prosthetics, known as Cheetah limbs, 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 scientists concluded Pistorius was able to run with his prosthetic blades at the same speed as able-bodied sprinters with about 25 percent less energy expenditure. Pistorius' blades gave him an energy return nearly three times higher than the human ankle joint offers in maximum sprinting, they said.
Riddell described Friday's ruling in Pistorius' favor as "groundbreaking," and said it raised questions about the future of paralympic sports.
"What does this do to the future of the Paralympics if he's allowed to run in the able-bodied Olympics? Is he actually doing a disservice to other Paralympic athletes? Does it cheapen the Paralympic Games?" Riddell asked.