The acting Venezuelan Attorney-General, Tarek William Saab, says an investigation will continue into corruption cases "buried" in the Public Prosecutor's Office while it was under his predecessor, Luisa Ortega Díaz.
In a televised news conference, Saab also urged the world to reject the campaign against Venezuela being waged by Ortega.
"This attorney general's office, during the administration of former prosecutor Luisa Ortega Díaz, reneged on its mission to become a platform for justice. Instead, it became a machine, an industry to extort and persecute innocent people and alleged culprits and to take their money," said Saab.
Saab accused Ortega of protecting large companies and power groups during her administration.
He said he will reopen cases, closed under the previous office, which implicated firms for allegedly making irregular use of foreign currency deals.
Saab said 80 percent of the scam cases were dismissed, and only 20 percent were prosecuted.
Most of those which were targeted involved small-scale fraud by individuals, rather than much bigger operations by companies.
"The intention was to manipulate evidence, leads, promote extortion, protect powerful companies and the use of criminal action for political purposes," Saab said, adding that Ortega had acted with "deliberate negligence."
Speaking in Brazil, Ortega repeated allegations that the Venezuelan President Nicolas Maduro and other senior government figures were involved in corruption with the construction company Odebrecht.
She reiterated her claim that she had proof, but offered none.
Ortega fled from Venezuela on Friday after alleging "political persecution."
She apparently traveled with her husband, German Ferrer, and at least one of her aides, by boat to Aruba and then on to Bogota by plane.
The Colombian government then announced that she was under its protection, and offered asylum to the couple.
But on Tuesday, she went to Brazil to take part in a meeting of attorney generals from the southern regional trading bloc, Mercosur.
The same day, Maduro said he would ask Interpol to issue a red arrest alert for her and German Ferrer, for their "serious crimes."
Maduro accused Ortega of enjoying a luxurious life style and having worked "for a long time" for the United States. On Wednesday, Venezuelan public television showed images of a police raid on Ortega's home in Caracas, apparently full of designer-label clothes and an extensive art collection, including an original by Andy Warhol.
On August 5, Ortega was temporarily suspended by the newly elected National Constituent Assembly.
The body announced that she will be investigated over accusations of "grave breaches of the law."
Ortega tried to have a number of judges removed from the Supreme Court, saying their appointment in December 2105 had been irregular because she, as Attorney General, had not been consulted.
She is also being investigated for her alleged support for opposition protests, which have claimed over 100 lives.
Ortega, once seen as a supporter of the Bolivarian Revolution and former President Hugo Chavez, began to distance herself from the government earlier this year.
She criticized the call for an ANC and unsuccessfully filed several petitions to have it blocked.