SAO PAULO (AP) — Brazil's former president has appeared in court to deny allegations he was part of a plot to obstruct a massive corruption probe by keeping a former oil company executive from revealing what he knew.

News media websites in Brazil published Tuesday's testimony by former President Luiz Inacio Lula da Silva, who told a federal court in Brasilia that he didn't even know Nestor Cervero, a former director of state oil company Petrobras.

Petrobras is at the center of a wide-ranging investigation into kickbacks and inflated contracts at state companies. Cervero was convicted in connection with the probe and is cooperating with prosecutors.

Prosecutors allege that Silva and several others plotted to offer Cervero money to keep him from giving evidence to authorities.