Inaki Urdangarin, who is married to the King's youngest daughter, and partner Diego Torres are accused of fraud and other crimes in connection with the disappearance of public funds, ThinkSpain reported.
Prosecutor Pedro Horrach said a large sum is needed to cover any possible legal liabilities of the defendants as their trial progresses. However, he said he was willing to consider bail in the range of $6.4 million to $7.7 million.
Defense attorney Mario Pascual Vives said he has not been officially informed of the bail application but considers $10.5 million to be "exaggerated."
Urdangarin, a former handball player and Olympic medal winner, is married to the Infanta Cristina.