Brazil's once hugely popular president Luis Inacio Lula da Silva underwent a new grilling Wednesday by the country's chief anti-corruption judge, Sergio Moro, in a case that could decide whether Lula can return to power.

Moro spent more than two hours questioning Lula in the southern city of Curitiba about alleged bribe taking from the scandal-plagued Odebrecht construction giant.

Lula, a frontrunner in the October 2018 presidential election despite multiple corruption charges, was as combative as ever, calling himself the victim of a "witch hunt."

"Despite considering this trial illegitimate and unfair, I prefer to speak," he told Moro, calling himself "the person who is more interested in the truth."

The 71-year-old, who was born in poverty and served two terms between 2003 and 2010, was greeted by several hundred leftist supporters on arrival at the courthouse.

Demonstrators wearing red shirts crowded around, shouting encouragement. About 1,500 police officers kept a close watch.

Moro is a key figure in the mammoth "Car Wash" anti-graft drive which has uncovered systemic bribery by corporations of Brazil's political class, as well as mass embezzlement from state oil company Petrobras.

Lula, arguably Moro's biggest target, is already a defendant in four other corruption trials.

And in July, Moro sentenced Lula to 9.5 years in prison after being convicted in a sixth trial of receiving a seaside apartment from the OAS construction company in return for help obtaining lucrative contracts with Petrobras.

The founder of Brazil's leftist Workers' Party, Lula is free pending appeal of that sentence and hopes to string out or defeat the other cases so that he can run for a third term next year.

But problems are mounting for the man whose presidency made him Latin America's new leftist giant.

- Corruption 'blood pact' -

Although Lula tops the polls, that is partly because campaigning hasn't started and name recognition gives him a head start. Also, his negative ratings are far higher than for other candidates.

A recent bus tour of his electoral heartland in the north-east of Brazil drew core supporters but not the kind of massive crowds that might have made judges afraid of tough action.

Lula says the corruption charges are concocted to prevent his return.

However, he has been hurt by testimony from his former economy minister and right hand man, Antonio Palocci, who told Moro last week that "the facts related in (the latest case involving Lula) are true."

Lula is accused of having Odebrecht buy the land for his Sao Paulo institute and provide him with an apartment in nearby Sao Bernardo do Campo.

Palocci said a "blood pact" was reached between the Workers' Party and Odebrecht in 2010 when Lula was handing over to his successor Dilma Rousseff, with the company giving the party the equivalent at that time of $171 million.

Lula says that Palocci, who has been sentenced to 12 years prison, is testifying falsely under pressure.

"Palocci has a right to want to be freed..., but what you can't do is put the blame on others if you don't want to assume responsibility for your own illegal acts," Lula testified Wednesday.

Lula was expected to address supporters in Curitiba after his court appearance. The crowd was considerably smaller than the 7,000 turnout for Lula when he was questioned by Moro in a previous case in May.

Despite Lula's claims to be a victim of a plot by Brazil's right to prevent any repeat of the left's decade in power, "Car Wash" prosecutors have gone after major figures across the political spectrum.

President Michel Temer, who took power last year after the impeachment of Rousseff, is himself currently fighting off multiple corruption probes.

Source: AFP