Algerian middle-distance runner Taoufik Makhloufi has been reinstated for the 1500m final after he had been disqualified from the London Olympics for allegedly not trying hard enough in the 800m heats.
Makhloufi had already qualified for Tuesday's 1500m final, where he was a likely medal contender, when he stopped running in the first lap of his 800 heat.
The race referee ruled that the 24-year-old African champion in the 800m was guilty of "failure to compete honestly with bona fide effort" but the Algerian federation insisted he had a knee problem and that organisers knew about it.
After assessing evidence of a games medical officer, the disqualification was revoked and the runner can compete in Tuesday's 1,500 final.
Olympic organisers released an official communication confirming the disqualification had been revoked.
"After reviewing evidence provided by a LOCOG (Games organisers) medical officer, the disqualification of athlete 1008 (Taoufik Makhloufi) from further participation in the athletics competition of the 2012 Olympic Games has been revoked by the IAAF technical delegates. Consequently, Mr Makhloufi is able to compete," it said.
The events on Monday came after eight badminton players were disqualified from the Olympics last week after a scandal over "throwing" matches.