The UK supplier of the prostheses used by all three medallists in last night's controversial 200m final has admitted that the IPC rules on blades allow athletes to experiment with height to improve their performance.

Oscar Pistorius, who keeps his blades the same length, hit out at the rules after he was beaten by Alan Oliveira, citing the Brazilian's long blades as a reason for the defeat.

Now Richard Hirons, Ossur's head prosthetist in the UK, has reiterated that the lengths are interchangable within the rules.

"Oscar could have done it too at the Paralympics, but he didn't," The Telegraph quotes Hirons as saying.

"The issue is not so much about length but the ability to vary length. Oscar's blades are sanctioned by the IAAF so that he can run in able-bodied and Olympic events and he does not change them for the Paralympics. So in that respect, he's got some parity.

"[Oliveira and bronze-medallist Blake Leeper] can move the heights up and down because they're looking to optimise their performance. They are acting within the rules and they are just to trying to optimise it. However it's off-putting if you're a competitor who decides to fix at a height."

Pistorius set the double-amputee world record in his heat, with a time of 21.30.