Brazilian police have arrested the government's leader in the Senate for allegedly obstructing the investigation into a corruption scandal at state-owned oil company Petrobras.

A Supreme Court official said Sen. Delcidio do Amaral of the ruling Worker's Party was arrested on Wednesday.

The official spoke on condition of anonymity because he was not authorized to speak to the press.

Under Brazilian law, the Supreme Court must approve any investigation of legislators or top officials in the executive branch. Any criminal charges or trials of such figures must also must be approved and judged by the top court.

The federal police also arrested Andre Esteves, the CEO of investment bank Grupo BTG Pactual. He's accused of obstructing the Petrobras corruption scandal.