Venezuela's recently ousted chief prosecutor has accused President Nicolas Maduro of participating in acts of corruption, saying she would turn over proof that would help other countries prosecute.
Luisa Ortega Diaz spoke during a meeting of Mercosur trade bloc prosecutors in the capital of Brasilia.
She was removed by a new, pro-government constitutional assembly in early August after breaking with the socialist government.
Ms Ortega fled abroad with her husband, whose arrest was ordered by the country's supreme court.
"I want to denounce, in front of the world, a grave situation in Venezuela: that of excessive corruption," she said.
"Because of that reason, (Maduro's administration) is violating the constitution and law to protect itself."
Ms Ortega said she had evidence implicating Maduro and other top officials in corruption involving Brazilian constructor Odebrecht and other companies, which she did not name.
However, she did not publicly give details.
Odebrecht has been at the centre of the massive "Car Wash" probe in Brazil involving kickbacks for contracts.
Over the past three years, dozens of Brazil's top politicians and businessmen have been jailed, including former Odebrecht chief executive Marcelo Odebrecht.
The investigation has led to prosecutions in several countries in Latin America where Odebrecht and other Brazilian construction companies operated.
Even if Ms Ortega possesses strong evidence, however, it is not clear whether it could hurt Mr Maduro's administration, which is already alienated from many of the region's countries.
While Brazil shares information with other countries related to the "Car Wash" investigation, authorities say they leave the prosecution of foreign nationals to justice officials in those countries.
Ms Ortega's visit came a day after Mr Maduro claimed that she was working with Washington to damage his administration and said Venezuela would ask for an international arrest warrant for her.
It was not immediately known if that had been requested or if it would even be considered.
The Mercosur trade bloc has suspended Venezuela due to the crisis there.
Before Ms Ortega spoke, Brazil Attorney General Rodrigo Janot described her ouster as an "an institutional rape" that eroded the independence of Venezuela's justice system.