A Spanish judge has formalized charges against Princess Cristina, King Felipe's sister, in a tax fraud and money laundering case, BBC News reports.

The princess, 49, was questioned in court in February about the business dealings of her husband, Inaki Urdangarin, and could now face trial.

However, an appeal has been lodged against the decision.

The judge's ruling will come as an embarrassment to Felipe VI, who came to the throne only six days ago.

The tax fraud case was one of several scandals that weakened the popularity of the Spanish monarchy and prompted the abdication of King Juan Carlos. Princess Cristina's appearance in court in Mallorca was unprecedented for the royal family and if she goes to trial, she could face up to 11 years in jail.

Judge Jose Castro has been investigating allegations that the princess's husband embezzled millions in public funds with a former business partner.

Urdangarin, who is the Duke of Palma, and Diego Torres were alleged to have received 5.6m euros ($7.5mln) by overcharging regional governments for organizing sporting events as part of a not-for-profit organization called Noos.