Lula supporters rally outside TV Globo headquarters

Supporters of former Brazilian president Luiz Inacio Lula da Silva rallied outside the headquarters of leading broadcaster TV Globo on Sunday, as populist anger over a corruption probe continued to grow.

Bearing the red flags of Lula's Workers' Party, the crowd that police estimated at more than 200 chanted, "To attack Lula is to attack me!"

The charismatic leftist leader was briefly detained on Friday in Sao Paulo amid a widening investigation into alleged embezzlement and bribery at state oil giant Petrobras.

He has dismissed corruption allegations as lies and called the legal case and media coverage a "show."

Protester Simone Simoes, a retired teacher, criticised media coverage of the Petrobras investigation, saying it was as if "the charges are true and the evidence is secondary."

Simoes said she was not a Workers' Party member but decried what she called "media and legal attacks" against the former president and his successor Dilma Rousseff.

Angela Maria Mees, a 61-year-old saleswoman, said Brazilian media were trying to dismantle party policies to improve income distribution and social equality.

"What shocks me is the level of selfishness among the elites," she said. "It's time to take action."

The opposition blames Lula for the gargantuan corruption network uncovered at Petrobras, which was systematically plundered during much of his presidency, with bribes funneling into the pockets of high-ranking politicians, including from the Workers' Party.

Lula has called on supporters to take to the streets, and says he may run for president again in 2018.