Princess Cristina, sister of King Felipe VI of Spain, is to become the first Spanish royal to face fraud allegations in court.
She is due to go before the Balearic Islands High Court to face the claims of tax fraud related to the business dealings of her husband, former Olympic handball player Inaki Urdangarin.
Prosecutors are demanding he should face up to 17 years in prison for defrauding his non-profit charity The Noos Foundation of more than £4.5 million of public money.
Lawyers are also pressing the princess to repay £475,000 of stolen cash.
Another aristocrat, the Duke of Palma, also faces up to 15 years in jail for his part in the affair.
At this stage, it is unclear whether the princess will face formal criminal charges or action to recover the cash she received from her husband without committing a crime.
The shadow of this corruption scandal has hung over the Spanish royal family for many months.
The royals have been tainted by accusations of fraud and tax evasion while the trials of others involved with Urdangarin have proceeded.
The Duke’s former partner Diego Torres, could be jailed for 17 years, while his wife Ana María Tejeiro must repay nearly £1 million of the misappropriated cash. She may also face money laundering charges.
Former Balearic Islands first minister Jaume Matas faces up to 12 years imprisonment for his part in the massive fraud. At least nine other suspects will be named in a 500-page petition seeking more than 100 years in jail for the group.
The Duke of Palma faces charges of misuse of funds, misconduct in public office, falsifying documents, fraud, administrative fraud, tax fraud and money laundering.
Prosecutors have offered to considerably reduce his jail time to six years if he pays back the £4.5 million of embezzled cash.
The Duke and other accused are said to have defrauded the foundation by charging huge fees for consultancy work that far outweighed the value of the advice they gave.