Video footage showed fans setting off flares and fireworks from the terraces of their Fortin ground in the final minutes of the match when Velez scored their two goals in a 2-0 win.
"The club received the notification from the AFA (Argentine Football Association)," Velez vice-president Julio Baldomar told TyC Sports.
"The flares could not have been taken in (to the ground) in flags or drums because there were so many," prosecutor Martin Lopez Zavaleta told TyC.
"We confiscated fireworks boxes in the ground which remains closed so Velez will not be able to play there on Thursday."
Velez are looking for another ground, likely to be River Plate's Monumental stadium or Boca Juniors' Bombonera, to stage Thursday's first leg of their Libertadores Cup quarter-final against Libertad of Paraguay.
Velez hold a four-point lead over second-placed Godoy Cruz in the Clausura championship and are Argentina's only remaining team in the Libertadores Cup, South America's equivalent to Europe's Champions League.
