Sao Tome and Principe fielded a player in the two-leg tie who hadn't submitted to a compulsory pre-match COVID-19 test or provided proof of a recent test, the Confederation of African Football said. That constituted a breach of CAF's medical rules. Sao Tome and Principe won the tie 4-3 on aggregate.
Mauritius was awarded Sao Tome and Principe's place in the main qualifying stage for the 2023 African Cup in Ivory Coast and will go into a group containing former champion Nigeria, Sierra Leone and Guinea-Bissau.
Those qualifiers start at the end of this month.
Mauritius, an Indian Ocean island better known for being a luxury holiday destination, has qualified for the African Cup only once before, in 1974. It lost all three of its games.
The Sao Tome and Principe federation was fined $10,000 for fielding the ineligible player, who wasn't named.
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