Spanish King Juan Carlos's son-in-law Inaki Urdangarin appeared in court today  to be questioned for the second straight day in a corruption case that has rocked the royal family.

The tall and lanky 44-year-old, who wore a blue suit and green tie, was accompanied by his lawyer as he arrived on foot at the court in Palma on the island of Majorca just before 9:30 am (0830).

Urdangarin, a former Olympic handball player who aquired the title of Duke of Palma when he married the king's youngest daughter Cristina in 1997, is suspected of embezzling public money paid to a charity that was under his control. He has denied any wrongdoing.

"I am appearing today to demonstrate my innocence," the duke told reporters when he arrived at the courthouse on Saturday to be questioned in a closed-door hearing.

"I have carried out my responsibilities and taken decisions correctly and with total transparency. My intention today is to clarify the truth of what happened. I am convinced that my declaration today will help to do so.

The allegations of royal involvement in the corruption case have raised indignation at a time when Spaniards are suffering the effects of an economic downturn, tough spending cuts and an unemployment rate of nearly 23 percent.

About 200 protesters, some wearing cardboard crowns, jeered as the duke entered the court on Saturday. A handful of protesters jeered as he arrived at the building on Sunday.

Urandangarin is suspected of having siphoned off money paid by regional governments to the Noos Institute, a charitable organisation based in Palma which he chaired from 2004 to 2006, for staging sporting events and conferences.

The royal family suspended Urdangarin from official engagements in December.