The sister of Dutch Queen Maxima committed suicide in her apartment in Buenos Aires, officials said.
The cause of the death was not immediately clear.
Zorreguieta worked for the government for the social development ministry in Buenos Aires and previously at a United Nations office in Panama and as a psychologist for an office on social policies at the president's office.
Queen Maxima, of the Dutch Royal Family, has chose to cancel her public appearances in the coming days in light of the awful news that her sister has passed away.
She's also a godmother to Princess Ariane, now 11 - the third and youngest daughter of the Dutch royals.
Aside from her royal sister, Zorreguieta has two brothers, Martin and Juan, and three half-siblings.
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It said Maxima was close to her sister, who was 13 years younger.
It's understood King Willem-Alexander will carry out next week's state visit next week to Estonia, Latvia and Lithuania alone, according to the BBC.
Inés and Maxima's father, Jorge Zorreguieta, died previous year at the age of 89.
"It is presumed that it was a suicide", a spokesman of the Dutch government told Argentinian newspaper La Nacion of the 33-year-old's death.