FIFA has opened disciplinary proceedings involving both the Brazilian and Argentinian football associations following the suspension of Sunday's World Cup qualifier.
The match was called off amid extraordinary scenes as officials, believed to be from Brazil's health authority, stormed on to the pitch in Sao Paulo shortly after kick-off over an alleged coronavirus breach by the visitors' England-based players.
FIFA president Gianni Infantino described the situation as "crazy" on Monday, and the world governing body's disciplinary committee will now investigate the circumstances which led to the suspension.
"Following the analysis of the official match reports related to the World Cup qualifier between Brazil and Argentina, FIFA can confirm that disciplinary proceedings have been opened involving both member associations," a statement from FIFA read.
"The two teams were asked to provide further information on the facts which led to the suspension of the match, which will be gathered and then thoroughly reviewed by FIFA's disciplinary committee. Updates will follow in due course."
According to ANVISA, the Brazilian Health Surveillance Agency, Argentina's four Premier League players – Cristian Romero and Giovani Lo Celso of Tottenham and Aston Villa's Emiliano Martinez and Emiliano Buendia – are alleged to have declared false information on official forms to the country's authorities and in doing so broken quarantine rules.
The Spurs duo can expect to be fined when they return to club duty, the PA news agency understands.
Top-flight and EFL clubs had announced they would not permit players to travel to countries on the UK Government's Covid-19 'red list', prompting Infantino to write to Prime Minster Boris Johnson to request exemptions which were not forthcoming.
It had previously been agreed with Villa that Martinez and Buendia would not be involved for Argentina's next match against Bolivia, so as to minimise their period of unavailability after arriving back in the UK and needing to quarantine.
Argentina later confirmed Martinez and Buendia had been authorised to now return to their club. While they will not feature against Chelsea in the Premier League on Saturday, they should be clear to play again for the visit of Everton on September 18.
However, it is understood Tottenham are currently unsure when Romero and Lo Celso are due back, the pair not having been given permission to join up with Argentina, and they will be hit with fines when they eventually return to club duties.
Romero, a summer signing from Atalanta, and Lo Celso started Sunday night's match, along with Villa goalkeeper Martinez, but Buendia was not in the matchday 23.
ANVISA said it had been confirmed, following passport checks, that the four players "failed to comply with the rule for the entry of travellers on Brazilian soil" after declaring they had not passed through the UK in the last 14 days, which would have necessitated quarantining on arrival.
The situation was considered "a serious health risk", with the local health authorities advised "to determine the immediate quarantine of players, who are prevented from participating in any activity and must be prevented from remaining in Brazilian territory".
The Argentina team responded to the entrance of the officials and the police by walking off the pitch and down the tunnel.
