German authorities have arrested Dutch banker Simon Leendert Verhoeven, a key figure in Spain's 'Caso Plus Ultra' financial investigation, and have notified Spain's Audiencia Nacional (the country's high court handling serious criminal and terrorism cases). The arrest marks a significant development in the long-running case, which centres on alleged irregularities surrounding a controversial state bailout of the airline Plus Ultra. The detention in Germany raises the prospect of extradition proceedings as Spanish investigators pursue accountability in one of the country's most politically sensitive financial scandals.