Ms Ortiz was an interior designer for a TV production company and had recently separated from her partner Antonio Vigo, whom she shared six-year-old daughter, Carla, with.
A spokesperson for the Dutch government confirmed the news to La Nación: "We can confirm that Inés Zorreguieta, sister of Queen Maxima of the Netherlands, died on Wednesday night".
The body of Ines Zorreguieta, 33, was found in her home in the Argentine capital.
Understandably, the Queen is shocked and very upset.
"It is presumed that it was a suicide", a spokesman of the Dutch government told the Argentinian newspaper, La Nacion.
The youngest sister of Queen Maxima of the Netherlands, has been found dead in her apartment in Buenos Aires. "It is intensely sad and heartbreaking news that can hardly be comprehended for those who stay behind", Prime Minister Mark Rutte said, according to The Guardian. I wish them all the strength necessary to carry this terrible loss together.
Queen Maxima is the wife of King Willem-Alexander of the Netherlands, who ascended to the throne in 2013.
Her father Jorge Zorreguieta, Argentina's former agriculture minister, died past year. Zorreguieta is believed to have taken her own life. King Willem-Alexander will travel alone to Estonia, Latvia and Lithuania.
She was also godmother to Queen Maxima's 11-year-old daughter Princess Ariane and the youngest daughter of Jorge Zorreguieta and María del Carmen Cerruti.
Zorreguieta was a psychologist who once worked for an office on social policies at the president's office.