Germany's federal cartel office on Tuesday launched an investigation into the German football association's (DFB) sale of tickets for the national team's matches at Euro 2016.

German fans wanting to watch their side in the tournament in France must first be members of the official fan club before purchasing tickets, hiking up their cost by an additional 40 euros ($45). The DFB's decision to combine the sales with membership that has a 10 euro sign-up cost and a 30 euro annual fee angered fans of the 2014 World Cup winners.

"Acquiring Euro 2016 tickets is already difficult for football fans as not everyone requesting a ticket gets one," cartel office president Andreas Mundt said in a statement published on Tuesday.