“This whole process is completely novel for Argentina,” said Manuel Garrido, a former corruption prosecutor who resigned in protest in 2009 after many of his cases had reached dead ends. “We really have no idea where it could lead.”

The current investigation began when a judge obtained notebooks containing the meticulous records kept by Oscar Centeno, the former driver of a powerful official in the Planning Ministry, who picked up and delivered bags of cash around town.

Since news of the notebooks became public, powerful figures in business and the government, implicated in the scandal, have come forward, describing to prosecutors a vast system of kickbacks involving government contracts said to have proliferated during the administrations of former President Néstor Kirchner and his widow and successor, Mrs. Kirchner, who governed from 2003 to 2015.

The notebooks, and other related evidence, exposed a “criminal organization made up of public officials” led by Mr. and Mrs. Kirchner, as well as by the former planning minister, Julio De Vido, that “between the years 2008 and 2015 sought the payment of illegitimate sums of money from numerous private citizens, many of them public works contractors,” according to a report published Friday night by the court of Claudio Bonadio, a federal judge, which is leading the investigation.

Argentines have been so riveted by the revelations since the notebooks emerged in late July that President Mauricio Macri compared the case to a binge-worthy television series.