"Sadly, over 10,000 unscrupulous applications have been made," Ticketmaster said in a statement.
In addition to the 14,200 places set aside for attendees of the original concert, around 35,000 additional tickets had been available for sale through the Ticketmaster. These tickets are reported to have sold out in just 20 minutes. The BBC reports that some tickets have appeared for sale on eBay, where they were listed at inflated prices.
Both eBay and Ticketmaster are working to block any reselling of the tickets, but that has slowed the process of getting tickets to genuine attendees of the first concert and has led to some frustration among fans. On Friday, Ticketmaster announced that it had processed 12,000 tickets for fans from the first concert.
"We will not stop until we have as many genuine fans at the show as possible," the statement read.
Sunday's show is due to take place at the Emirates Old Trafford cricket ground, which houses around 50,000 people for a music event. Grande had pledged to return to Manchester to raise money and honor the victims of the attack, which the Islamic State claimed responsibility for.