LAGOS, Nigeria -- The Athletics Federation of Nigeria says it has banned 1968 double Olympic champion Lee Evans of the United States from coaching for four years for giving a minor performance-enhancing substances.

The AFN says an investigation found that Evans and another coach gave the girl substances last year which "may have been responsible" for her failing a doping test.

The federation also banned the other coach for life after the young athlete, who was not named, said she collapsed after he took her to a doctor, who injected her with an unknown substance.

Evans, 67, won gold in the 400 metres and 4x400 relay at the Mexico City Olympics, both in world-record times. His 400 time of 43.86 seconds stood for 20 years. The AFN said he was working as a consultant in Nigeria.