Brazil's leftist icon Luiz Inacio Lula da Silva on Monday opted to stay behind bars rather than apply for home detention, as he maintained his innocence of corruption charges, his lawyers said.

The ex-president has been incarcerated at the federal police headquarters in the southern city of Curitiba since April 2018, after he was sentenced to eight years and 10 months in jail for accepting a bribe.

After completing one-sixth of his sentence on Monday, he was eligible under Brazilian law to apply for house or semi-open detention, which would allow him to leave prison during the day.

But Lula decided to forgo the option in order to "pursue the full restoration of his freedom, along with the recognition that he was a victim" of a contaminated judicial process, his defense team said in a statement to AFP.

The Supreme Court last month voted to suspend the transfer of Lula to a regular prison until after it rules on whether Justice Minister Sergio Moro, who was Lula's convicting judge in 2017, was biased.

That decision could lead to a review of Lula's case.

Moro, the powerful judge behind the so-called Car Wash corruption probe before he was appointed to President Jair Bolsonaro's cabinet, has been accused of conspiring with prosecutors to keep Lula out of the 2018 election, which the ex-president was favored to win.

Scores of high-profile politicians and business leaders have also been caught up in the years-long investigation.