Oscar Pistorius secured his first gold medal of the 2012 Paralympics by anchoring a South African T42-46 4 x 100-metre relay victory.

The South African team won in a new world record time of 41.87 seconds.

Brazil and defending champions USA pressed hard, but both nations were disqualified. As a result of the disqualifications, China and Germany took silver and bronze.

Earlier Pistorius, the defending 100-metre champion qualified with the second quickest time for the T44 final.

It was the 25-year-old's first appearance on the track since a surprise T44 200-metre defeat on Sunday, where he had to settle for silver behind Alan Oliveira.

Pistorius raised concerns over the length of his opponent's blades, claiming they were "not running in a fair race".

However, the South African later apologised for the timing of his outburst.