German magazine Der Spiegel says it has seen a letter insinuating that three members of West Germany's 1966 World Cup football team may have broken doping rules with cold treatment medicine.

The magazine reports in its current issue that historians at Berlin's Humboldt University uncovered a letter from Nov. 29, 1966, in which FIFA medical committee chairman Mihailo Andrejevic informed West German Athletics Federation president Max Danz of slight traces of an ephedrine-based medicine found in three players.

Ephedrine, a decongestant, is also a stimulant and was on FIFA's list of banned substances at the time.

West Germany lost to host England 4-2 in the final.

Humboldt's press office says it wasn't immediately aware of who had uncovered the letter.