Leaked documents show Irish company paid a tiny fee for rights to Spain midfield star

The issue of third-party ownership has been hotly-debated in footballing circles for some time now.

After West Ham pulled off the stunning double signing of Carlos Tevez and Javier Mascherano in their second year back in the Premier League - and the subsequent complaints from the relegated Sheffield United - such agreements were banned from the English game. But it is still possible on the continent for teams to take on players without holding all of their rights. Clubs such as FC Porto and Atletico Madrid have managed to stay competitive despite smaller budgets than their European rivals largely thanks to the help of third-party investors. But even though both clubs have made tidy profits from the likes of Jackson Martinez and Radamel Falcao, the sale of the rights of some of their top youngsters doesn't always work out. Atleti midfielder Koke has been labelled the "new Xavi" by many and looks to be a regular in the Spanish national team for years to come. It seems unlikely that the 24-year-old will stay at the Vicente Calderón Stadium for the rest of his career, with both Barcelona and Real Madrid likely suitors. And while any move for Koke would come at hefty price, Atletico would miss out on almost a third of the fee as they apparently sold 30% of the Spaniard's rights to an Irish investment fund for the lowly sum of €3m (£2.4m) just three years ago, according to Football Leaks. We're no mathematicians, but that means the Spanish club valued one of Europe's hottest prospects at just £8m as a 21-year-old. And while Ireland have taken advantage of the so-called 'Granny Rule' in the past, we doubt the argument that Koke is legally 30% Irish would allow him to switch allegiances for Euro 2016.