It was reported that the National Police Corps (Cuerpo Nacional de Policía) swooped on Sanz following allegations of swindling. Two others have also been arrested.
Sanz briefly served as Bernabéu president in the late 90s before Florentino Pérez arrived and set about his policy of 'galácticos'.
Sanz, meanwhile, moved south to Málaga, where he bought a controlling stake in Málaga CF. His son Fernando is club president.
The Sanz family have yet to comment on this revelation.
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