[6] In December 2022, he was sentenced to six years in prison for an unlawful business partnership with former Argentine president Cristina Fernández de Kirchner while she was in office.
The move was reportedly caused by political persecution,[8] his father having apparently had to leave his home province following the coup against President Arturo Frondizi.
[9] Kirchner was at the time serving his last year as mayor of Río Gallegos and beginning a crucial campaign for governor, a position he would end up holding from 1991 to 2003.
[9] In April 2013, Deputy Francisco De Narváez called Báez "a person of great intimacy with the Kirchner family.
[17] On April 14, 2013, journalist Jorge Lanata of Periodismo para todos ("Periodismo para todos"), a news program aired on Argentina's Channel 13, presented a report entitled "La ruta del dinero K" ("The K Money Trail"), with "K" standing for the late Argentinian president Néstor Kirchner.
Lanata's report included a videotaped testimony by financier Federico Elaskar and a hidden-camera recording of businessman Leonardo Fariña in which these men described large-scale illegal financial manipulations by members of the Kirchner circle, including Báez, that involved the transfer of about 55 million euros over a six-month period to Switzerland and other foreign tax havens.
Allegedly, at Báez's direction, Fariña orchestrated a plan whereby the funds were sent abroad via Elaskar's financial firm, SGI.
[18] Asked on hidden camera whether Báez was an associate of Kirchner's, Fariña said yes, and added that "in politics there are no front men, only operators."
[18] In a subsequent interview with Rolando Graña on América Noticias, however, Elaskar claimed that there had been no money laundering or death threats, and that everything he had said on Lanata's program was untrue.
Lanata replied to these claims by saying that Fariña was "not the brain" of the operation and that on his next show he would provide evidence Báez was the real mastermind.
[10][19] After the Lanata program was aired, several opposition legislators called on public prosecutor Carlos Gonella to investigate the accusations against Báez.
[30] Báez's lawsuit against Fariña and his wife, Karina Jelinek, on charges of slander was dismissed in early July by judge Raúl García.
[31] In December 2013, the Argentinian newspaper La Nacion reported that seven Báez companies had signed documents agreeing to rent 935 rooms a month at the Alto Calafate Hotel throughout 2010 and 2011, whether or not they were occupied.
La Nacion additionally revealed that Báez had paid at least $3.2 million to Kirchner in "rent" for Las Dunas, an inn in El Calafate, and that he had paid a total of $14.5 million in "rent" for the two hotels, plus the La Aldea Hotel, during 2010 and 2011, even as Báez was receiving large sums from the federal government for public works projects.
[32][33] It also emerged in December 2013 that Báez, during the previous ten years, in Santa Cruz alone, had purchased tracts of land amounting to at least 263,000 hectares, or 13 times the size of the Federal District.
[32] Also in December 2013, Báez asked for an injunction that would prohibit the media from publishing anything about his business or personal ties to Kirchner.
[37] The Swiss ambassador to Argentina, Johannes Matyassy, said in January 2014 that a criminal investigation into Báez's financial activities in Switzerland was progressing.