MADRID -- A judge investigating suspected fraud who had subpoenaed the Spanish king's daughter postponed her testimony after prosecutors appealed the subpoena on Friday.

Princess Cristina had been ordered to testify April 27 at a court on the island of Mallorca by Judge Jose Castro.

Castro delayed the hearing after prosecutors argued there is insufficient evidence of her involvement in an alleged plot to embezzle public money. He did not set a new hearing date.

The court summons is a first for a member of the king's immediate family.

The investigation centers on whether the 47-year-old princess' husband, Inaki Urdangarin, and his former business partner took advantage of their royal connections to funnel about 5 million euros ($6.4 million) in public funds via the nonprofit Noos Institute they ran into private businesses they also controlled.

A panel of judges of the provincial court of the Balearic Islands, where the case is being investigated, must now rule on the appeal. The process could take weeks.

Should the appeal be turned down, the princess will be defended by Miquel Roca, a prominent lawyer and former Catalan politician. Roca, 72, was one of seven "fathers" (writers) of the Spanish Constitution, in force since 1978, and member of Parliament for almost 20 years.

Castro said in court documents on Wednesday that the princess was a board member on two of her husband's companies and there was evidence she was aware that he had used her royal status and connections in making deals.

He said both Urdangarin and the princess had benefited equally from those deals and that the princess could be considered an accomplice.

Urdangarin, 45, has already been questioned twice by Castro since the probe began two years ago.

Castro argued that the princess had to be questioned for his investigation to be complete and also to show that justice treats everyone equally.

Although no one in the case has so far been charged with a crime, Cristina now joins her husband and his partner in being named as a person officially under suspicion of involvement in corruption.

This is another blow to the royal household, which has been through a torrid time in recent months.

For decades King Juan Carlos was largely admired for having shepherded Spain from a military dictatorship under Gen. Francisco Franco to a modern democracy.

The monarchy's fortunes began a sharp decline last year when it was revealed that the 75-year-old king broke his hip while on an unannounced luxurious African safari to hunt elephants at a time when ordinary Spaniards were suffering a recession, sky-high unemployment and government-imposed austerity measures.

Juan Carlos has appeared frail in recent months and in March he had surgery for herniated discs in his lower spine - his fourth operation in a year.

Urdangarin is a former professional handball player and an Olympic medalist. The deals he and his business partner brokered included organizing seminars and sports events as a tourism lure. However, some events were allegedly charged for but never took place or were charged at unusually high rates.

The judge recently set joint bail of 8.2 million euros ($10.5 million) for Urdangarin and former business partner Diego Torres. Bail has not been paid and the court has now begun a process to freeze property and other assets.

The royal family last year sidelined Urdangarin from all official royal activities, and has removed him from the family website.

• Read more articles by HAROLD HECKLE

Order Reprint