Last month, law enforcement officials in Spain said they had broken up a major match fixing ring in tennis. The Guardia Civil said 28 players competing at the lower levels of tennis were implicated. It's alleged that a group of Armenians had bribed the players to fix matches. File on 4 reveals the inside story of how players and betting gangs are seeking to corrupt the lower tiers of the sport. In many cases, a player only has to lose a set or certain games - not the whole match - to get paid. Players and fixers communicate on social media as matches get underway to ensure the correct outcome is achieved. The rewards can be significant with players sometimes being paid thousands of pounds - often much more than they can earn in prize money. For the betting gangs who have placed money on a guaranteed outcome, the pay off can be much greater. Two years after File on 4 first revealed concerns about match fixing in the game, the programme looks at how the tennis authorities have responded to the issue and examines the measures put forward by an independent panel to reduce the risk of corruption. Reporter: Paul Connolly Producer: Paul Grant Editor: Gail Champion Photo credit: AFP / Getty Images