(CNN) -- South African "Blade runner" Oscar Pistorius has apologized for the timing of his complaints about the length of his rivals' prosthetic limbs after his shock loss in the 200-meter sprint at the Paralympic Games in London.
Minutes after losing the race to 20-year-old Brazilian runner Alan Fonteles Cardaso Oliveira on Sunday, Pistorius accused the gold medalist and others in the race of wearing "unbelievably long" blades.
"You can't compete on stride length. You saw how far (Alan) came back so, you know what, we're not racing a fair race here, but I gave my best on a great night," he said.
Early Monday, Pistorius apologized for the timing of his comments but said that he believed "there is an issue here."
"I accept that raising these concerns immediately as I stepped off the track was wrong," Pistorius said in a statement. "That was Alan's moment and I would like to put on record the respect I have for him."
Oliveira passed the South African in the final stretch to take the gold medal in a time of 21.45 seconds. It was slower than the world record of 21.30 set by Pistorius in the qualifying heat Saturday, but fast enough for a decisive win against the race favorite who clocked a time of 21.52.
Like Pistorius, Oliveira, is a double-amputee who runs with the aid of prosthetic limbs.
Immediately after the race, Pistorius expressed incredulity at Oliveira's dash in the race's final seconds.
"I think Alan's a great athlete but you can't come back (that much). I run just over 10 metres per second and I don't know how you can come back -- by watching the replay -- from eight metres behind on the 100 to win. It's absolutely ridiculous," Pistorius said.
Pistorius also accused bronze medalist American Blake Leeper of stretching, if not breaking, the rules. "The guy came down literally overnight and made his blades longer. His knee height's like four inches higher than what it should be."
The South African said he'd attempted to raise the issue of blade length with the International Paralymic Committee (IPC) in the weeks before the race but his concerns had "fallen on deaf ears."
The IPC issued a statement saying that all athletes competing in amputee events had their prostheses measured before the race and all complied with IPC Athletics Rules.
Oliveira said it was "difficult" to hear allegations of cheating coming from someone he regarded as a "great idol."
Asked whether Pistorius was just a bad loser, he said: "(He is) not a bad loser. Pistorius is a great athlete... I still do not know with whom he is picking a fight. It's not with me."
Oliveira denied he had cheated and attributed his performance to training. "It's not just about the protheses, there is training behind. I get upset to hear this kind of thing. I'm inside the rules (of the International Paralympic Committee). I came here to celebrate and do not enter in any polemics," he said.
It was a sentiment echoed by Leeper. "(Pistorius) has his opinion. You know, we go by the IPC rules. I'm following the rules. I feel like I'm not cheating, I do the best I can. I still work hard every day -- I train six days a week, two or three times a day. So I feel it's not the legs. For him to say it's the legs, I disagree. But he's a great runner. I truly support him and what he does, honestly."
After a short meeting with Pistorius after the race, the IPC's director Craig Spence said the committee's science and medical director Peter Van Der Vliet would meet the athlete at a later date in a "non-emotional environment."
"The IPC respects the significant role Oscar has played in raising the global profile of Paralympic Sport since his Games debut in 2004. Therefore we are more than willing to give him an opportunity to air his views," Spence said in a statement.
Pistorius later appeared to back away from his earlier statements, tweeting an image of him shaking Oliveira's hand and the message: "Congratulating Alan of Brazil for his 200m win.. The fastest last 80m I have ever seen to take it on the line. pic!"
Just weeks ago, Pistorius made history by becoming the first double-amputee to contest an able-bodied Summer Olympics when he competed at the 2012 Games in London.
While the runner failed to win a medal, his presence on the track was lauded as an example of victory over adversity and a lesson in dedication to a goal.
After initially being refused permission to compete against able-bodied competitors, Pistorius hired a legal team to prove that his artificial limbs didn't give him an unfair advantage.
Born with a congenital abnormality, Pistorius had both his legs amputated below the knee at 11 months of age and now runs on specially-adapted carbon-fiber limbs.
Later this week, Pistorius will compete in the men's T44 100-meters -- set for Wednesday and Thursday -- and the T44 400-meters -- Friday and Saturday -- both of which he won at the Beijing Paralympics four years ago.