The third and final programme in the series Foreign fields examines the growing social impact of hooligan groups in Italy and Argentina - as they become increasingly politicised and organised.

The programme gains unprecedented access to the shadowy and often violent world of the hooligan groups attached to two of the world's most glamorous clubs - the Irriducibilli of Lazio in Italy and the Barras Bravas of Boca Juniors in Argentina.

Filming openly and undercover with the hooligan leaders, Foreign Fields examines the growing social impact of hooligan groups around the world - as they become increasingly politicised and organised.

In Argentina, five people have already died this season in football-related shootings, with dozens more casualties. The season was even suspended against a backdrop of widespread social disorder.

Using extraordinary footage filmed with the hooligans, the police and during riots around the stadiums this season - the film shows the growing influence of these groups on the clubs and the players themselves.

Players like Diego Maradona, who talks for the first time about his friendship with the hooligans of Boca - his first and favourite club.

We also talk to players and hooligans in Italy about the growing influence of racist and far-right groups on the terraces that the hooligans control.

The Lazio hooligans: the Irriducibilli - now have their own merchandise, and businesses - organising all the stadium banners and meetings with the players - many of them international stars - and the club.