High Court judge Santiago Pedraz ordered the two men detained because he said there was a significant flight risk given their "huge financial means" and they could destroy evidence.

Pedraz questioned Villar, a senior president of world football governing body FIFA, and his son throughout the day.

Also examined were federation vice-president Juan Padron and Ramon Hernandez Baussou, general secretary of the Tenerife federation.

Police arrested the four men on Tuesday following raids on federation headquarters and other sites as part of a fraud probe launched last year.

They face charges including falsifying documents, misappropriation of funds, collusion and administrative breaches linked to skimming profits from international friendly games and channelling the funds to Gorka Villar.

Investigators were also probing whether national federation funds had been used to bribe regional officials to vote for Villar at federation elections for president, according to Spanish media reports.

Villar, 67, a UEFA vice president, has headed the Spanish federation since 1988.

Under his watch Spain became one of the dominant forces in world football, winning two European championships and the 2010 World Cup.
But his critics say his period in charge was marked by ethical issues and an autocratic management style.

Following his re-election in May, El Pais newspaper denounced his "despotic" management and bemoaned his close ties to FIFA and UEFA leaders embroiled in corruption probes.