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  Isaac Makwala told BBC Sport his "heart was breaking" after being denied entry to Tuesday's 400m final in London.
  The 30-year-old, who was withdrawn by organisers the IAAF "due to a medical condition", questioned how officials could know he was ill, without tests.
  He said he felt he was "sabotaged".
  Tuesday's race was won by Olympic champion and world record holder Wayde Van Niekerk, who - in the week eight-time Olympic sprint champion Bolt retires - has been described as the "new superstar of athletics".
  "There is something fishy they do not want to tell us," said Makwala. "It is not that I was sick, there is something more to it.
  "How can they just look at you and see you are sick? If they had tested me I would not have that problem, but they just assumed.
  "Usain Bolt is out now so the IAAF wants someone to be the face of athletics."
  In response, athletics' governing body told BBC Sport: "There is nothing we want more than extraordinary competition in these championships.
  "We freed up the competition schedule to allow this to happen, specifically between these two athletes by allowing the opportunity to double up at 200m and 400m."
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  Van Niekerk's winning time was 43.98 seconds.
  At a Diamond League meeting in Monaco in July, Makwala ran 43.84, but still finished behind the South African (43.73).
  "After I saw him cross the line on Tuesday I was like, this was my time. He ran a normal time. I was on shape for a faster time," Makwala said.
  "The British would never have allowed it if I was Mo Farah or Wayne Rooney.
  "In Botswana we have to pay to train, this is not like Britain. I feel this has been a waste of money and training."
  Briton Farah won his third consecutive gold World Championship 10,000m gold on Friday.
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  The IAAF acknowledged Makwala's absence was "a sad case" but said its medical staff examined the athlete, and notes taken by a doctor showed he had been vomiting over an 18-hour period.
  It said it was under instruction to quarantine athletes who showed symptoms of a "very virulent" norovirus outbreak.
  Pam Venning, head of medical at the IAAF, told BBC Sport on Tuesday: "I have to trust my doctors. My role is to ensure the healthcare of all the athletes here and it's a very infectious and very virulent disease."
  In a later statement, the governing body said: "The team doctor, team leader and team physio had been informed following the medical examination that the athlete should be quarantined for 48 hours and would therefore be missing the 400m final on Tuesday."
  Venning said "all the other teams" with affected athletes had adhered to IAAF instructions.
  Public Health England says 30 athletes and support staff have been affected by sickness at the Tower Hotel in London - though the hotel is not the source of the outbreak.
  The IAAF has insisted it gave clear communication to the Botswana delegation that Makwala would not be allowed to run following a medical examination.
  But Botswana officials said they had received no explanation as to why Makwala was not allowed entry, and had not been told to keep the runner in quarantine.
  The country's Olympic boss Falcon Sedimo told BBC Sport: "There has been no official communication, no formal communication from the IAAF at all. We found out from the media.
  "There have been no medical tests at all, it's just generalised assumptions because of the outbreak of sickness and he has just one of those symptoms."
  Botswana medical team member Simon O'Brien said Makwala showed no symptoms of the bug and blamed "poor communication" from the IAAF for the athlete missing the race.
  "He's fit, he's very well, he's prepared to run, and he's just being kept away by the IAAF," said O'Brien, who insisted there was no sign of the illness during the time he spent with Makwala.
  After winning gold, Van Niekerk said: "I would love him to have his fair opportunity. I believe he would have done very very well. I've got so much sympathy. I really wish I could give him my medal."
  British former 400m runner Dai Greene tweeted: "I was really ill in the build-up [to the 2010 Commonwealth Games] in Delhi as were so many others. But nobody stopped us racing or tested us."
  BBC commentator Allison Curbishley, another former 400m runner, defended the IAAF's decision to bar Makwala from competing, but described its handling of the situation as "a real mess".
  "When he presented himself as being ill, of course the IAAF had to go to their protocols. Illness had already been an issue as of the Sunday, so they were clearly on edge and didn't want it to spread," she told BBC Sport.
  "The whole thing comes down to communication. The IAAF did not handle it brilliantly, and if the situation arose again I think it would be dealt with very differently.
  "As athletics fans we were robbed of a great head-to-head, and what we might see happen now is if an athlete has the same symptoms later this week they may well keep it quiet."
  Several German and Canadian athletes staying at the Tower Hotel fell ill last week.
  A further 30 Germans due to arrive on Tuesday were moved to other hotels.
  German triple jumper Neele Eckhardt collapsed but was well enough to compete on Saturday, and took part in Monday's final.
  The Ireland team, who are also staying at the hotel, have confirmed that one athlete - 400m hurdler Thomas Barr - has been affected.
  The Tower Hotel said investigations conducted with environmental health officers and the IAAF had shown the hotel was "not the source of the illness". That has also been confirmed by Public Health England.
summary: The Botswanan athlete who was barred from running at the World Championships as organisers tried to halt a norovirus outbreak says the same would not have happened to Mo Farah or Usain Bolt.