North Korea is blaming football's worst doping scandal in almost two decades on using steroid-laced medicine from musk deer glands to treat injuries from a lightning strike at a training camp for the Women's World Cup.
FIFA President Sepp Blatter said on Saturday that after two North Korean players were caught during the tournament, three more positive results came in when the world football federation took the unprecedented decision to test all members of the squad.
"This is a shock," Blatter told a news conference.
"We are confronted with a very, very bad case of doping and it hurts."
The last doping case at a major event came at the men's 1994 World Cup in the United States, when Diego Maradona was kicked out after testing positive for using a cocktail of banned substances.
Colombia reserve goalkeeper Yineth Varon has meanwhile been suspended for failing an out-of-competition test just before the Women's World Cup in the wake of undergoing hormonal treatment. It was the first doping case in the history of the women's Cup.
All attention, however, turned to the North Korean cases on Saturday.
"The North Korean officials said they didn't use it to improve performance. They said they had a serious lightning accident with several players injured and they gave it as therapy," Michel D'Hooghe, head of FIFA's medical committee, said in an interview.
A North Korean delegation told Blatter and D'Hooghe early on Saturday that the steroids were accidentally taken with traditional Chinese medicines based on musk deer glands.
After North Korea lost its opener against the United States, team officials first claimed that lightning had struck several players on June 8 during a training camp at home.
The case will be taken up by FIFA's disciplinary committee. Players face a ban of up to two years for such infractions.
Defenders Song Jong Sun and Jong Pok Sim tested positive for steroids after North Korea's first two group games and were suspended for the last match. The team was eliminated in the first round after another loss to Sweden and a draw with Colombia.
The names of the three other players would be made public only at a later stage, FIFA said.
The gland in question comes from musk deer living in a large swath of Asia from Siberia to North Korea.
Doping officials have been concerned about such naturally occurring substances in recent years.
FIFA investigators who discovered evidence of doping in the North Korean samples found themselves in uncharted territory. Experts from the World Anti-Doping Agency were called in to confirm the breach of doping rules.
"It was very complex," FIFA chief medical officer Jiri Dvorak said, especially since the type of steroids had "never before appeared and never before been determined."
All experts concluded there were "positive findings of an unknown origin," Dvorak said.
After the first two cases were discovered, doping officials made an unannounced visit to North Korea's last match to impose the provisional suspension on the two players. They then said all the players would be tested.
But it was the team's medical officer had provided the breakthrough, following extensive testing that took until late Friday.
"(The officer) gave us a sample that she described as classical or traditional medicine that is often used in North Korea," Dvorak said.
"We can really say with far-reaching confidence that these steroids were the result of this so-called Chinese traditional medicine."
The musk gland extract "it is not part of the world of doping," Dvorak said. "It is really the first case in which this has been discovered."