Adele has teamed up with a face value ticket platform for her sold-out Wembley Stadium concerts after fans paid up to a reported £25,000 for a previous tour.
The London-born singer set up a ticket resale scheme on her website for her four shows next summer, which sold out on Friday morning.
Adele will perform at the stadium - which has a capacity of 90,000 - on June 28, 29 and July 1 and 2 in The Finale shows.
Shortly after the tickets - which ranged from £45 to £95 - were snapped up, dozens of listings appeared on secondary ticket sites with hiked prices.
One listing on auction site eBay was asking for £450 for a seat to her June 28 show.
Adele, who has previously branded touts "terrible people", appointed Twickets as her official resale partner for the Wembley concerts.
A statement on the Hello singer's website warns fans that any tickets resold through any channel other than Twickets "will not be accepted".
It adds: "You risk having them cancelled and being denied entry to the show."
Earlier this year, her management spoke out for a change in the law to help those trying to clamp down on ticket sale profiteering.
In February, an £85 seat to see Adele at the London O2 was reportedly being sold online for £24,840.
Twickets, which launched in 2011, allows fans to buy and sell spare tickets at face value or less.
The issue of secondary ticket sites has drawn attention recently as One Direction and Arctic Monkeys joined with music trade bodies to urge the Government into action against online ticket touts.
Last month, You Me At Six frontman Josh Franceschi told MPs on the Culture, Media and Sport select committee the future of live music depending on a change in the law.
And award-winning singer-songwriter James Bay said secondary ticketing sites "suck" at the Q Awards last month.
After collecting Best Solo Artist award at the ceremony, which was sponsored by Stub Hub, the Hold Back The River singer said: "Apologies to my fans for ever having to deal with secondary ticketing sites. I hope we see the end of them. They definitely suck."
Fan Fair campaign manager Adam Webb said: "We encourage resale of tickets at face value.
"This is fantastic news that one of the biggest artists in the world is encouraging her fans to sell tickets fairly at face value."