Fifa has accused Malaysia of falsifying citizenship documents so seven foreign-born players could play for the national team.
Football's world governing body had fined and suspended the players in late September and on Monday released a report justifying its action.
Fifa said the Football Association of Malaysia (FAM) had forged birth certificates to make it look like the players' grandparents were born in Malaysia. This, the body said, "constitutes, pure and simple, a form of cheating".
But FAM said the discrepancies arose from an "administrative error" and that it would appeal Fifa's penalties. It maintained that the players were "legitimate Malaysian citizens".
Fifa's "grandfather rule" allows foreign-born football players to represent countries that their biological parents or grandparents were born in. This aims to prevent national football teams from simply importing foreign players to boost performance.
