Brazil has launched a truth commission to investigate human rights abuses committed during the country's 20 years of military dictatorship.

The country is one of the last in Latin America to look into the dark period known as "the dirty war," when many leftists were tortured and killed, by authoritarian regimes.

The seven members of the new truth commission got a standing ovation after being sworn in, the CBC's Connie Watson reported from Rio de Janeiro.

'Brazil deserves the truth, future generations deserve the truth.' —President Dilma Roussef

The commission will spend two years unearthing the facts and laying bare some of the state's most violent history. Between 1964 and 1985, Brazil's military regime killed or "disappeared" as many as 500 people.

President Dilma Rousseff was among the thousands of militants who were jailed and tortured. She was near tears as she launched the commission.

"Brazil deserves the truth, future generations deserve the truth," she said, speaking in Portuguese. "But above all, those who lost friends and family and who are still suffering as if they were dying again every day deserve the truth."

Several high-ranking generals in the audience applauded, but former army brass call the commission nothing more than a chance for the leftists in power to get revenge. They point out that one of the commissioners was the president's lawyer when she was jailed.

Brazil's past is not as bloody as the brutal regimes in Argentina and Chile, which killed thousands of leftists. The truth commissions in those countries led to high-profile trials of key figures. That's unlikely to happen in Brazil, Watson reports.

"No matter what the investigators find, Brazil's amnesty law protects those who committed atrocities at the time from ever being prosecuted."