A member of a group searching for loved ones who disappeared during Argentina’s dictatorship says this week’s revelation that a missing granddaughter had been found was erroneous.

On Thursday the human rights organization Anahi announced that 39-year-old Maria Elena Wehrli was in fact the long-lost granddaughter of Maria Isabel Chorobik de Mariani. Mariani is a founder of the Grandmothers of Plaza de Mayo group, which looks for the disappeared.

But her spokesman and biographer Juan Martin Ramos Padilla said Saturday that the initial test conducted at a private facility was mistaken, and state-sanctioned DNA testing has since determined there is no genetic link between the two women.

Former military figures have been convicted of organizing the theft of babies from political prisoners detained and often executed during the 1976-83 dictatorship.