Emi Martinez, Emi Buendia, Gio Lo Celso and Cristian Romero are accused of giving false information to health authorities after flying in from Caracas
Four Argentina players have been ordered to go into quarantine and then leave Brazil just hours before the two nations clash in Sunday's World Cup qualifier.
Emiliano Martinez, Emiliano Buendia, Cristian Romero and Giovani Lo Celso travelled with their nation for the September international round despite the Premier League's restrictions on travel.
Now they face missing out on the upcoming repeat of July's Copa America final triumph due to irregularities.
What was said?
"Following the report that four Argentine players entered Brazil in defiance of the country's sanitary regulations, allegedly giving false information to the Brazilian health authority, Anvisa met with representatives of the Health Ministry and Disease Control Coordination of Sao Paulo's State Health Department," a statement explained on Sunday.
"After meeting with health authorities it was confirmed, following revision of the passports of the four players involved, that the athletes broke the rules for the entry of travellers on Brazilian soil, which decrees that foreign travellers who have been in the United Kingdom, South Africa, Northern Ireland and India in the last 14 days are banned from entering Brazil.
"The players in question declared they had not been in any of those four restricted countries in the last 14 days. They arrived in Brazil on a flight from Caracas which landed in Guarulhos (Sao Paulo). Then, unofficial reports came to Anvisa over alleged false declarations from the travellers.
"Anvisa considers the situation a severe health risk, and has therefore instructed local health authorities to impose immediate quarantine measures on the players, who are banned from engaging in any activity and will be unable to remain in Brazilian territory."
The bigger picture
Argentina's quartet were among the few Premier League players able to arrive in South America, with Brazil losing no fewer than nine players as a result of the Premier League's decision not to release travellers bound for countries on the UK's red list.
Martinez and Lo Celso both started in Thursday's 3-1 victory over Venezuela in Caracas, with Buendia on the bench and Romero hoping to return on Sunday after serving a one-match suspension.
Reports of the quartet's infraction emerged following their arrival in Brazil, although CONMEBOL maintained on Saturday that their presence was permissable as they formed part of the national team's bubble.
"Our tournaments are played inside a sanitary bubble which excuses delegation from going into quarantine for 72 hours," CONMEBOL general secretary Gonzalo Belloso told Clarin.
"The World Cup qualifiers are played with the same model. We have told the Brazilian authorities and the CBF [Brazilian Football Confederation] who are the hosts and must guarantee the game is played."
Following Anvisa's statement, police were seen outside the Argentina team hotel in Sao Paulo as negotiations continued at a furious pace just two hours before the game was scheduled to kick off at Arena Corinthians.