Lawyers for former president Cristina Fernández de Kirchner said Tuesday they will call in human rights observers to counter alleged "violations" carried out by officials, prosecutors and judges investigating her for corruption.
Her defence team plans to ask the Inter-American Commission for Human Rights to send observers to examine the investigation led by Federal Judge Claudio Bonadio.
Gregorio Dalbón, a lawyer for the former president, said the investigation into the sitting sentaor for Buenos Aires Province "is violating all legal procedures."
A key complaint is the refusal to allow one of her lawyers to be present at a search of her home last week.
Raids were carried out at three of Fernández de Kirchner's private residences in Recoleta, Buenos Aires City, and Patagonia after the Senate voted to temporarily suspend her immunity. The former president also voted in favour of the repeal.
"Human rights and due process have been subjugated in one way or another," Dalbon told the AFP news agency.
Fernández de Kirchner, 65, served as president from 2007 to 2015, succeeding her late husband Néstor Kirchner as head of state. She is the highest-ranking official being investigated in the so-called 'bribery notebooks' case, which has already ensnared dozens of former government officials and top businessmen.
Prosecutors believe a total of US$160 million may have been paid by business leaders to Fernández de Kirchner, her late husband and her allies and supporters in return for state contracts during a 10-year period from 2005-2015.
Fernández de Kirchner is being investigated in five other cases too.
Nonetheless, she remains hugely popular in Argentina and claims her political opponents are trying to derail a possible run for the presidency next year.