London - South Africa's Oscar Pistorius, the first double amputee athlete to compete at an Olympics, insisted on Saturday he has earned the right to be at the Games, blasting critics who think otherwise.
The 25-year-old, fondly known as 'Blade Runner' because he runs with carbon fibre prosthetic running blades, has not been universally welcome with some observers believing he has an unfair advantage.
"You'll find a journalist who has not approached the story properly, or somebody with the title of professor or doctor who wants to make a name for himself," he told the Daily Telegraph.
"He will argue that water is dry, or that orange used to be green. They will try to be controversial for the sake of it.
"Honestly, this is not something I can give much more energy to. I would be answering these questions for days."
Pistorius will make history in London when he becomes the first amputee sprinter to compete in a Games after being selected for South Africa's individual and relay 400 metres.
Pistorius, who will also defend his titles in the 100m, 200m and 400m at the Paralympics next month, has a personal best time of 45.07sec in the 400m.
But he is not getting carried away by his chances at the Games.
"A decent position in the semi-final," he said as he summed up his ambitions.
"I wasn't happy with my performance at the World Championships in Daegu (in 2011).
"I had an unbelievable race in the heats, but misjudged the semi and finished last. This time I'll have to go flat-out from the start.
"I'd like to show people that if you put the hard work in and you believe in yourself, then you can do whatever you want to. I still find it strange, I suppose, when I say to someone, 'Can you just pass me my leg?' But I don't ever think about my disability.
"Putting on my legs is like putting on my shoes. I understand that's how some people might think differently, but I hope that in London, their perceptions open up."