Adele tickets are being sold with huge mark-ups on secondary websites despite a massive effort by the artist to combat ticket touts.

Hundreds of tickets to see Adele at Wembley stadium next summer appeared for resale on so-called “secondary ticketing” sites such as Viagogo and StubHub even before they went on advance sale on her official website.

The Guardian reports that tickets were being sold for as much as £9,000; however, at the time of writing the highest price that appeared on each site appeared to be in the realms of £2,000, not including booking fees.

Adele and her team have been trying to clamp down on touts for over a year.

Last year an industry analysis found that the singer had “saved fans £4m”' by taking tour tickets out of touts’ hands.

More than 500,000 fans followed her request to pre-register on a website to qualify for tickets to her UK concerts in spring 2016.

Working with the ticketing website Songkick, Adele and her management team identified accounts that they believed belonged to touts, and successfully de-registered around 18,000 of them before the UK pre-sale tickets became available.