Former president Luiz Inacio Lula da Silva has been in jail since April for accepting a luxury seaside appartment as a bribe

Sao Paulo (AFP) - Former Brazil president Luiz Inacio Lula da Silva will be questioned next week in relation to another Operation Car Wash case in which he is accused of corruption and money laundering.

The 73-year-old is already serving a 12-year prison sentence for accepting a bribe in a separate case related to the ongoing and wide-ranging Car Wash investigation into graft.

Questioning Lula, currently incarcerated in Curitiba in the south of Brazil, will be judge Gabriela Hardt, who has taken over the Car Wash investigation from the man who jailed the ex-president, Sergio Moro, recently named Justice Minister by president-elect Jair Bolsonaro.

That appointment was controversial as left-wing icon Lula’s incarceration prevented him from running in a presidential election he was widely expected to win, having led polls with more than twice the number of vote intentions as his nearest challenger, Bolsonaro.

Lula’s lawyers have asked for his release and the suspension of the charges against him, accusing Moro of bias.

“Lula is the victim of a judicial witch-hunt unleashed by an agent wearing a judge’s gown … who sought to cancel his freedom and rights,” said the lawyers.

Moro replied to that on Tuesday in a press conference insisting that Lula “was convicted and jailed because he committed a crime and not because of the elections.”

In this latest case against Lula, he is to answer questions about refurbishments to a farm believed to belong to him in Atibaia, Sao Paulo state, and paid for by major construction companies between 2010 and 2014 in exchange for big Petrobras contracts.

Lula’s defense insists the property doesn’t belong to him and has accused authorities of harassment.

Hardt has this week been questioning businessman Marcelo Odebrecht, the former CEO of the Odebrecht construction giant, who has struck a plea bargain with investigators to testify against others in return for a reduced sentence.

In December, Marcelo Odebrecht was released into house arrest at his luxury Sao Paulo home just two-and-a-half years into a 10-year sentence that had already been reduced from 19 years.

He claims that the farm refurbishments were directly connected to Lula.

The head of the Workers Party has been behind bars since April 7 for having accepted a seaside apartment in return for his mediation in contracts with state oil giant Petrobras.

On top of these two cases, he is implicated in four more but insists he is innocent of all accusations and has denounced the charges as political persecution.

Dozens of public officials have been caught up in the Odebrecht corruption scandal, including incumbent President Michel Temer, while the construction company has agreed to pay 2.7 billion reis ($700 million) to the Brazilian government as punishment for bribing officials in order to win public works contracts.