Instead of celebrating his double success, he broke down in a television interview before demanding that he be shown more respect by sprint rival Isaac Makwala.

The Botswanan was stopped from running against Van Niekerk in the 400 meters, having been diagnosed as suffering from norovirus, and had suggested there was a conspiracy to keep him from running.

"There is something fishy they do not want to tell us," Makwala told the BBC when he was denied the chance to race on Tuesday. "It is not that I was sick; there is something more to it. ... Usain Bolt is out now, so the IAAF wants someone to be the face of athletics."

Van Niekerk took this to be a reference to him -- the negative twist added to a night of a fascinating 200-meter final, which was surprisingly won by Turkey's Ramil Guliyev; Jareem Richards of Trinidad and Tobago took bronze.

"It really did upset me a bit, especially the amount of respect I've shown each and every competitor I compete against, including Makwala," Van Niekerk said in a postrace news conference.

"I've always shown him massive respect, and for him to come out and, I think, mention my name among something fishy happening in the IAAF, pointing me out as the favorite, knowing how hard I've been working the last few years.

"If I was an overnight success, and this was my first gold medal, I could have accepted a statement like that. But I have been putting out great performances the last two years now, including this competition's double. I definitely deserve way more respect from my competitors."

The U.S. 400-meter great Michael Johnson had also fueled the conspiracy theories when he appeared on the BBC as an analyst on Tuesday, saying: "Wayde van Niekerk is an IAAF favorite and now the only person that was his challenger has been pulled out. Conspiracy theories are going round. Who is behind this?"

Van Niekerk said his success Thursday made it "unlucky" for Johnson, for whom he has a lot of respect, but he was most upset by Makwala.

The IAAF might not have been happy with the sixth-place finisher in the 200-meter final, either, as he continued to express his anger and disappointment at being denied the chance to race the 400 meters. This, even though he had been granted a solo time trial at the shorter distance once he was declared fit.

Makwala told reporters after Thursday's race: "When I came to this championship, my aim was to win the 400. I had a 100 percent chance to win the 400. I feel so angry. I had a bigger chance in the 400 than the 200. It was obvious I was going to get a medal."

The episode left Van Niekerk, a guy who has been tapped to succeed Bolt as the sport's biggest icon and drag it to a more positive place, with a bad taste.

"We are not here to make friends," he said. "We are here to compete, and I've learnt a great lesson now. I definitely will be taking the future a bit differently and focusing on myself and not needing such negative figure.

"I wouldn't say it [what was said] affected me, I just expected more from someone I've been competing with for the last few years now. I gave him his dues when he was ahead of me. He's broken my record, I've broken his record, and there's been continuous respect, so for him to come out with such a statement is a bit disappointing."

The one upside of the whole sorry saga was that it appears to have made the 25-year-old even more determined to scale new heights.

"After 400 meters, there was quite a lot of people that felt I didn't deserve it," Van Niekerk told the BBC. "I'm glad I could come out today and put out a good fight. I really believe this is the beginning of so much more that I can achieve.

"I work just as hard as every other competitor I compete against. I show everyone else respect, and I think I didn't get the respect I deserved after the 400 meters. It's only the beginning. I am going to put in so much more hard work and show my dominance."