FIFA has launched disciplinary proceedings after Ecuador were alleged to have fielded an ineligible player during their successful qualifying campaign for the Qatar World Cup.

Chile, who failed to reach the showpiece in Qatar later this year, lodged a complaint with football's world governing body alleging that full-back Byron Castillo was not Ecuadorian and had been born in Colombia.

The football federation of Chile alleged "use of a fake birth certificate, false declaration of age and false nationality".

The 23-year-old Castillo played in eight qualifiers, including both of Ecuador's matches against Chile -- a 0-0 draw in Quito in September 2021 a 2-0 victory for Ecuador in Santiago two months later.

If FIFA rule against Ecuador, those matches could be forfeited allowing Chile to leapfrog into the final qualification place for Qatar 2022.

Chile finished seventh in the South American World Cup qualification table, seven points behind Ecuador in the fourth and final automatic berth for Qatar.

Chile were five points behind fifth-placed Peru, who now face an intercontinental playoff against either Australia or the UAE to reach the finals.

"FIFA has decided to open disciplinary proceedings in relation to the potential ineligibility of Byron David Castillo Segura," football's governing body said in a statement.

Ecuador's FA said that Castillo was "duly registered with the competent legal authority" and had "all valid national documents".