The sight of Paulo Maluf, a former mayor of São Paulo, and his son Flávio, bleary-eyed in the back of a police car on their way to jail in the middle of the night, was one many Brazilians thought they would never see.

Mr Maluf is accused of spiriting overseas more than $160m (€137m, £92m) from public works contracts. He and his son were arrested in September for allegedly conspiring to influence witnesses. Both deny any wrongdoing.