More than 10,000 "opportunists or touts" falsely claimed they were at the scene of the Manchester attack in order to get free tickets for the upcoming benefit concert, according to Ticketmaster.
Shocked social media users have hit out at ticket scalpers, labelling them "scum of the earth" and "sickening".
Ariana Grande is returning to the city where the suicide bombing happened at her concert in May for the charity event, where she will be joined by Katy Perry, Justin Bieber and Miley Cyrus, among other high-profile guests.
Ticketmaster set aside free tickets for the show - which takes place Sunday, June 4 (local time) - for 14,200 people who were at the Manchester Arena concert when 22 people were killed in last month's attack.
However, the company says over 25,000 people applied for the special passes, with many tickets quickly being put up for sale by scalpers on websites like eBay and Viagogo.
"Sadly, over 10,000 unscrupulous applications have been made," said Ticketmaster.
"[We are] doing everything we can - including extending today's deadline - to ensure that tickets go to the actual fans and not the opportunists or touts who have also been applying for free tickets."
Another 35,000 tickets on sale to the general public for the event sold out in 20 minutes.
Social media users called out those selling the tickets for a profit on resale websites as "sickening" and "disgusting".
Ticketmaster says it is cancelling tickets of those who are reselling, "wherever possible".
Newshub.