A black market selling thousands of Premier League tickets has been revealed by a BBC investigation.

Companies based at a number of overseas locations, including in a Swiss town with a population of 4,000, are behind it.

They are thought to be using memberships and computer software to obtain tickets at scale through clubs’ online ticket platforms.

The resale of tickets is illegal in the UK, and the Premier League names the websites on an “unauthorised list”., external

Despite this, BBC Sport was able to buy tickets easily through the black market for four of last weekend’s games. The practice has been described as “endemic” in English football.

Sunday’s Manchester derby was sold out weeks ago, but we bought a pair of tickets in the City end days before the match.

We also made purchases for fixtures at Arsenal, Everton and West Ham.

At all four matches, our journalists were able to use the tickets to gain entry to the game.

But for others who have used these websites, this is not always the case, with fans telling BBC Sport they paid for tickets that didn’t let them into games.

The tickets cost us two to four times the face value, and some were sent via UK phone numbers on Whatsapp, on one occasion with strict instructions not to speak to stewards.

The findings have prompted calls for clubs, the Premier League and government to do more to crackdown on the black market.

There is concern that the scale of the market is making it harder for supporters to get tickets from official sources at face value – and also creating a potential safety threat to strict segregation rules.

In response, clubs said they were working hard in this area, and had already cancelled tens of thousands of memberships and tickets.