Spain's Princess Cristina has been summoned to testify as a suspect in a corruption case, a judicial source said Wednesday, dealing a damaging blow to the prestige of the royal family including her father King Juan Carlos.
It is the first time a member of the Spanish royal family has been called to appear in a court of law on suspicion of wrongdoing.
The 47-year-old princess must testify on suspicion of influence peddling on April 27 at the court in Palma on the Mediterranean island of Mallorca, the judicial source said on condition of anonymity.
"The royal household does not comment in any way on judicial decisions," a spokesman for the royal family told AFP.
The case, which was opened at the end of 2011, is centred on allegations of embezzlement and influence peddling against her husband, former Olympic handball player Inaki Urdangarin, and his former business partner, Diego Torres.
The pair are suspected of syphoning off money paid by regional governments to stage sports and tourism events to the non-profit Noos Institute, which Urdangarin chaired from 2004 to 2006.
Until now, the princess had avoided being dragged formally into the case, although accusations had been mounting up against her.
The summons by Judge Jose Castro will be seen as extremely damaging to the royal family, already slumping in the popularity polls.
The 75-year-old Spanish king is credited with steering Spain to democracy following the death of dictator Francisco Franco in 1975 but his standing had already taken a hit over the corruption probe implicating his son-in-law and over a luxury elephant-hunting safari he took in Africa last year at a time of record unemployment in Spain.
An opinion poll published last month showed almost 57 percent of Spaniards felt the king should abdicate in favour of his 45-year-old son Prince Felipe, once Juan Carlos recovers from surgery he had in March for herniated discs in his lower spine, his seventh operation in three years.
Urdangarin, who has not been charged with any crime and maintains his innocence, sought to distance his wife and the rest of the royals from his business dealings when he was questioned in court in February by the judge leading the investigation.
But his former business partner then provided the judge with emails that were leaked to the press appearing to show that Urdangarin regularly consulted his wife -- a member of the board of the Noos Institute -- about the body's affairs.
Carlos Garcia Revenga, the longtime personal secretary to Princes Cristina and her older sister Princess Elena, was questioned by the judge after Torres submitted another batch of e-mails that suggested he was actively involved in the Noos Institute's dealings.
Princess Cristina, who works as the director of social welfare programmes at Barcelona-based financial services group La Caixa's charitable foundation, has kept a low profile since the scandal broke.
The easy smile she was known for has been replaced by a serious expression during her rare outings.
A fan of various sports, especially sailing, Princess Cristina -- the seventh in line to the Spanish throne -- met Urdangarin at the 1996 Olympics in Atlanta where he was competing with Spain's handball team, which won a bronze medal.
In 2009 Princess Cristina and her husband, along with their four children, moved from Barcelona to Washington where Urdangarin took up a job as an executive director of the US subsidiary of Spanish telecoms giant Telefonica.
The couple, who were given the title of Duke and Duchess of Palma when they wed, were living in the United States when the allegations of corruption at the Noos Institute first broke in Spain.
"All we want to do is live a normal life and you won't let us," she said when approached by a Spanish television reporter at a Washington supermarket in February 2012, just before her husband was questioned in court in Palma for the first time.
In August last year the couple and their four children returned to Barcelona, where they own a mansion in the exclusive Pedralbes area that reportedly cost around six million euros ($8.0 million).