Personalised tickets at Euro 2016 are "ineffective" according to Helmut Spahn, the former head of the German FA's security.
Spahn's comments were made after right-wing extremists were pictured inside the Stade Pierre Mauroy in Lille as Germany beat Ukraine 2-0 on Sunday.
He served as the head of security for the 2006 World Cup in Germany, and in 2011 joined the Qatar-based International Centre of Sport Security (ICSS), where he currently holds the position of an executive director.
Speaking to Spiegel in the wake of violence prior to Germany's opening match of the tournament, when two people were injured as German hooligans attacked Ukraine supporters in the city centre, Spahn criticised UEFA's ticketing system.
"The way the system of personalised tickets is implemented it is totally ineffective," Spahn said. "The option to pass tickets on virtually makes a serious identity check impossible."
At least one far-right extremist with a local stadium ban was pictured inside the stadium as TV footage showed Michael Bruck [Michael B], a Dortmund city council member for the right-wing party Die Rechte. He is banned from attending matches at Borussia Dortmund's Westfalenstadion and was expelled from the Bundesliga club.
Wer feiert in #Lille? Rechtsextreme: Michael Brück von "Die Rechte" und Kamerad Deyda. #ViveLaMannschaft #GERUKR pic.twitter.com/TZ0yENYnr7
- Sebastian Weiermann (@SWeiermann) June 12, 2016
But, speaking to WDR, a spokesperson for the ZIS, a German police division for sports related violence, said that stadium bans do not apply for matches outside of Germany.
Another picture taken earlier in the day showed B. mingling with hooligans showing the Hitler salute in Lille city centre.
A police spokesperson told Spiegel some 300 German hooligans were in Lille. Eighteen hooligans from the city of Dresden and a further three from Kaiserslautern were stopped by German federal police close to the French border on Sunday.
In 2013, a right-wing extremists network of hooligan firms, acting under the name GnuHooters and then under the name HoGeSa (Hooligans against Salafists), was formed and has since marched through Germany on several occasions. In October 2014, violence erupted during a demonstration in Cologne, with nearly 50 police injured.