BUENOS AIRES, Argentina -- Argentine officials say the youngest sister of Queen Maxima of Holland has been found dead in her Buenos Aires apartment.

The death of 33-year-old Ines Zorreguieta was confirmed Thursday by a person at the prosecutor's office in charge of the case, who spoke on condition of anonymity for lack of authorization to speak to the press.

The cause of the death was not immediately clear.

Zorreguieta was a psychologist who worked for an office on social policies at the president's office.