The EU is thought to have lost more than €10 billion to fraud over the last two decades, and yet its anti-fraud and anti-corruption agencies have long lacked the teeth to root out the problem. Could that be about to change? Stephen Sackur speaks to Romanian Laura Codruta Kövesi, the EU's first public prosecutor. She has enhanced powers to tackle transnational crime. But if member states refuse to play ball, how can she succeed?