* King's son-in-law charged with embezzlement, other crimes
* Foundation overcharged to put on sports business events
* Corruption cases have shaken Spain
By Inmaculada Sanz
PALMA DE MALLORCA, Spain, Feb 23 (Reuters) - The Spanish king's son-in-law appeared before a judge on the island of Mallorca on Saturday to respond to charges of tax fraud in a six-million-euro embezzlement case that has eroded public support for the once-popular royal family.
The scandal and other corruption cases in which politicians are accused of taking millions of euros in bribes have enraged Spaniards at a time when unemployment has soared to 26 percent in a deep recession.
Inaki Urdangarin, a former Olympics handball player who is married to the king's daughter, the Infanta Cristina, is accused of using his powerful connections to win public contracts to put on events on the Mediterranean island of Mallorca and elsewhere in Spain.
His Noos Foundation is suspected of overcharging for organising conferences about the business of sports and hiding the proceeds abroad.
Dozens of police officials guarded the courthouse in Palma as Urdangarin got out of a car and walked down a 30-metre access ramp into the building for the closed-door hearing where he will be questioned by Examining Magistrate Jose Castro.
Near the courthouse, a few hundred protesters chanted and held up signs reading "down with the monarchy" and "they call this a democracy but it isn't".
More than a hundred journalists were also on hand.
In Spain's legal system, lengthy pre-trial investigations are carried out by an examining magistrate, or judge. Urdangarin, 45, is charged with fraud, forgery, embezzlement and corruption. If convicted, he could face a prison sentence and fines.
Urdangarin was first charged and called in for questioning in 2011, but a trial could still be months or years away as the judge continues his probe and adds or dismisses charges.
Judge Castro was expected to question Urdangarin for most of the day on Saturday and perhaps into the early hours of Sunday.
Urdangarin is fighting an order that he and a former business partner in the Noos Foundation post bail of 8.2 million euros. His assets could be seized if he does not meet bail.
The judge will also question on Saturday Carlos Garcia Revenga, former treasurer for the Noos Foundation and also private secretary to Urdangarin's wife, Cristina, 47.
Judge Castro is trying to find out how much the Infanta Cristina knew about the business of the foundation. A criminal indictment of the king's daughter would be an unprecedented accusation against a royal in Spain.
Cristina is the only one of five directors of the Noos Foundation that has not been charged with a crime. (Writing by Fiona Ortiz; Editing by Nick Macfie)