Former president Néstor Kirchner, who is running for a seat in Buenos Aires province Lower House, and Justice Minister Anibal Fernandez said Francisco De Narváez must testify to "end with this corporative matter."

"When any member of the ruling party is summoned it's an investigation, but when someone from the opposition is summoned everybody says it´s a persecution. We must end with this corporative matter," Kirchner said, urging De Narváez to "give a republican and civic example" and show at court to give testimony.

Meanwhile, dissident Peronist Deputy Francisco de Narváez, who is heading the slate of centre-right Unión PRO coalition for Congress, repeated he would challenge Federal Judge Federico Faggionato Marquez after he had summoned him to testify in the investigation of ephedrine trafficking in the country.

"I won't let him drag me to the mud, I won't let him mistreat my name, I won't let him attack us, in defense of the millions of Argentines that I am representing," De Narváez said.