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, 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Equatorial Guinea appealed against an unpublished Fifa disciplinary committee decision relating to the Malabo match and the follow-up proceedings have not been finalised.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 on Sunday did not name the Ethiopian, Togolese or Equatoguinean footballers being investigated nor give a date when the findings will be released. – AFP