Spanish King Juan Carlos' youngest daughter Cristina is worried about her husband the Duke of Palma's upcoming corruption hearing, the duke's lawyer said Wednesday after meeting with her.

"It is logical she should be worried," said Mario Pascual Vives, lawyer for Duke of Palma Inaki Urdangarin, after meeting with Princess Cristina the previous day in the northeastern city of Barcelona.

"It was essentially a courtesy call so that I could confirm a few things after my latest meetings with Urdangarin," the lawyer told Spanish media.

The so-called "Palma Arena affair" centres on the suspected embezzlement of public funds during the construction of a velodrome in Palma de Majorca between 2005 and 2007.

An investigation concluded that the cycling track had an unjustified cost overrun of 41 million euros.

That led authorities on the archipelago to uncover other cases of suspected embezzlement of public funds, including one allegedly involving the royal son-in-law Urdangarin.

The 43-year-old ex-Olympic handball player is scheduled to appear in court on February 25 as a suspect in the probe into corruption at a non-profit organisation, Instituto Noos, which he headed between 2004 and 2006.

The investigation centres on the payment of several million euros to Instituto Noos for organising a tourism and sports conference in 2005 and 2006.

Urdangarin has denied any wrongdoing and his wife is not accused of any involvement.

In December, the royal family suspended the duke from official engagements and the palace's highest civil official Rafael Spottorno gave an unprecedented rebuke, telling Spanish media Urdangarin's behaviour "does not seem exemplary".