The judge investigating a corruption case implicating Iñaki Urdangarin has ordered the Spanish king's son-in-law and his co-defendant, former business partner Diego Torres, each to post an 8.1-million-euro (nearly $11-million) civil bond.

The amount covers possible legal liabilities in the case of alleged diversion of public funds to the now-defunct Noos Institute, a purportedly non-profit entity once headed by Urdangarin, who is married to King Juan Carlos's youngest daughter, Princess Cristina.

Jose Castro, a judge in the Balearic Islands, said in his ruling issued Wednesday that assets in that same amount would be seized if the defendants do not post the required bond within five days.

Urdangarin is scheduled to appear before the judge to answer charges of tax fraud on Feb. 23, nearly a year after testifying regarding the alleged siphoning off of some 6.1 million euros in Balearic Islands and Valencia regional government funds to the Noos Institute between 2004 and 2007.

The royal son-in-law and his business partner also are under investigation for alleged breach of public duty and other crimes.