German carmaker Volkswagen AG spied on Brazilian union leaders throughout the 1980s and passed on information gathered about wages and other sensitive topics to the country's military dictatorship.

The company also monitored some of its own workers during that time, according to documents seen by Reuters.

One of the most prominent targets that VW spied on was union leader Luiz Inacio Lula da Silva, who rose to the Brazilian presidency from 2003 to 2010 and remains a powerful politicians.

Last month the Brazilian National Truth Commission found signs that dozens of companies, including Volkswagen and other foreign automakers, helped the dictatorship identify union activists to suppress labor unrest.

Commission leaders say they have evidence that Volkswagen went beyond what was found last month and collected their own intelligence on the unions and shared it with the government.

The documents show that Volkswagen passed on comprehensive accounts of several union meetings and handed over plans for strikes and demands for better wages and working conditions.

This information was used by Brazilian police to monitor, harass and arrest union leaders, aiming to prevent future labor unrest, said Sebastiao Neto, a member of the National Truth Commission.

"These documents show with exceptional clarity how companies expected the government to help them solve their problems with their workers," said Neto, who is in charge of commission's research of links between companies and the military.

The companies who are found to have contributed to human rights violations of their employees could face civil lawsuits of demand for reparations, according to Brazilian prosecutors.

The documents were found by historians in Brazil's national archive and will be included in the Truth Commission's final report, which is due in December, according to TeleSur. Neto said the historians were hired by a local union to work with the commission.

Volkswagen has responded by saying it will investigate these charges.

"Volkswagen is acknowledged to be a model for coming to terms with its corporate history," the company said in a statement. "The company will handle this topic in the same way."