Fifa is probing whether Ethiopia, Togo and Equatorial Guinea each used an ineligible player in 2014 World Cup qualifiers.
The standard punishment given by the world football governing body is that a guilty team surrenders any points they gained and their opponents are awarded a 3-0 victory.
Fifa found Burkina Faso, Gabon and Sudan guilty of fielding ineligible players in qualifiers for Brazil and opponents Congo-Brazzavile, Niger and Zambia, respectively, were declared 3-0 winners.
Matches being investigated are the 2-1 win by Ethiopia in Botswana and the 2-0 win by Togo at home to Cameroon during June, and the 4-3 home victory of Equatorial Guinea over the Cape Verde Islands last March.
Equatorial Guinea appealed against an unpublished Fifa disciplinary committee decision relating to the Malabo match and the follow-up proceedings have not been finalised.
Should Group A winners Ethiopia lose the three points, they would no longer be certain of qualifying for the play-offs with South Africa and Botswana back in contention.
Cameroon, who trail Libya by two points in Group I, could take a one-point lead into a September match with the North Africans if Togo broke World Cup regulations.
A verdict against Equatorial Guinea would put the Group B qualification of Tunisia on hold as the five-point gap between them and second-place Cape Verde would shrink to two points.
The Fifa statement did not name the Ethiopian, Togolese or Equatoguinean footballers being investigated or give a date when the findings will be released.
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