The International Olympic Committee (IOC) said Friday they want to investigate doping procedures in North Korea after two players tested positive for anabolic steroids at the women's World Cup.

Professor Arne Ljungqvist, chairman of the IOC's Medical Commission, has said he will look into the matter after North Korean defenders Song Jong-Sun and Jong Pok-Sim failed doping tests at Germany 2011.

The pair were removed from the lineup for North Korea's goalless draw with Colombia in Bochum on Wednesday and with their team eliminated, the squad left Germany early on Thursday morning to return home.

Ljungqvist says he wants to know more about testing in North Korea, but is realistic about finding out more about doping checks in the Asian totalitarian state.

"I understand the mistrust of others, but I do not really know much about doping controls in this country, which has a closed society like no other in the world," said Ljungqvist at the 123rd IOC Session in Durban, South Africa.

Football's governing body FIFA had the remaining 19 members of the North Korean team tested for banned substances after their final group game and have asked for Song and Jong's B samples to be examined.

In total, there have now been three failed doping tests at the women's World Cup after Colombian player Yineth Varon failed an out-of-competition test in Leverkusen on 25 June.