Spanish King Juan Carlos's son-in-law Inaki Urdangarin was up before a judge Saturday for the second time in a corruption case that is casting a growing shadow over the royal family.

Urdangarin appeared in court on the Mediterranean island of Majorca for questioning over allegations that he embezzled millions of euros of public money paid to a company he managed.

Carlos Garcia Revenga, longtime secretary of Urdangarin's wife, the king's youngest daughter Cristina, was also due to be questioned Saturday by Jose Castro.

Urdangarin and his former partner Diego Torres are suspected of syphoning off money paid by regional governments to the Noos Institute, a charitable body which Urdangarin chaired from 2004 to 2006.

The money was meant to cover the cost of staging sporting and tourism events.

Both men have denied any wrongdoing and have not been charged with any crime. The judge is investigating the case with a view to possibly putting them on trial.

Urdangarin arrived dressed in a grey coat and striped scarf at the court in Palma and made no comment to a waiting crowd of reporters before going inside for the closed-door hearing with his lawyer.

A crowd of protestors massed nearby yelling in anger at the perceived corruption.

Torres implicated the royal palace in the scandal when he was questioned a week ago by the judge, according to unnamed sources cited by Spanish newspapers.

They published emails supposedly sent by Urdangarin which appeared to indicate that the 75-year-old king backed and closely followed his business career.

The revelations are a big embarrassment for the royal family which has distanced itself from Urdangarin since the scandal erupted at the end of 2011.

Garcia will be questioned about his role at the Noos Institute and "his possible work as an advisor" to Urdangarin, a court source said.

The emails have reportedly been added to the investigating judge's file. Castro questioned Urdangarin for the first time as part of his probe in February last year.

The palace has said it would keep Garcia in his post and would take no action until he goes before the judge.

As Spain grapples with a record unemployment rate of 26 percent and steep government spending cuts, the allegations of corruption have taken their toll on the monarchy.

General support for having a monarchy in Spain fell to 54 percent, six points lower than a year ago and "a historic low", according to a poll published last month in daily newspaper El Mundo.

This month the court in Palma said it would begin freezing assets belonging to Urdangarin and Torres after they missed a deadline to pay bail of 8.2 million euros ($11.1 million).

Since the bail was applied in a civil case the two will not go to jail for not paying the sum.

Urdangarin, a 45-year-old former Olympic handball champion, acquired the title of Duke of Palma when he wed Cristina in 1997.

On top of the corruption scandal, King Juan Carlos, 75, has seen his health suffer in recent years.

The palace announced that the king will have surgery for a slipped disc on March 3 at a Madrid clinic -- his seventh operation in three years.

The royal palace on Friday said the king was not planning to abdicate despite a press report to that effect and following calls by several regional politicians for the king to step aside for his son Felipe, 45.