Cape Town - The South African Paralympic Committee has registered a formal complaint with the International Paralympic Committee (IPC), reigniting the row over whether Oscar Pistorius's rivals are breaking the rules by swapping their prosthetic blades mid-competition. The Guardian reports that SA officials decided to raise the issue again, despite Pistorius apologising for the "poor timing" of his comments after being beaten in the 200m for the first time in nine years by the Brazilian Alan Oliveira.South Africa asked the world governing body to investigate whether Pistorius's rivals had changed the height of their blades between the heats and the finals, which is against the rules.The IPC then investigated the claims by asking coaches in the athletes' village whether their athletes had switched their blades."When we put the allegation to the coaches about different-sized running blades, there was a look of shock because it's difficult to do. There is no evidence they were competing on different-sized running blades," Craig Spence, the IPC's director of communications, said.Pistorius returns to the track on Wednesday when he will aim to defend his T44 100m title and goes in the heats from 21:00 (SA time).Organisers have billed the showpiece straight sprint as the race of the competition, with all eight finallists capable of running under 11secs. Pistorius won the T44 title in Beijing four years ago in a photo finish from his great rival Jerome Singleton of the United States, a former National Aeronautics and Space Administration (NASA) intern who won silver in Beijing.