By Guillermo Parra-Bernal and Leonardo Goy
SAO PAULO/BRASILIA (Reuters) - Brazilian police arrested the ruling party's leader in the Senate and the chief executive of Latin America's biggest investment bank on Wednesday on suspicion of obstructing an investigation into corruption at state-run oil company Petrobras.
André Esteves, the CEO and controlling shareholder of BTG (L:BTG) Pactual SA (SA:BBTG11), was arrested at his home in Rio de Janeiro and television images showed him arriving handcuffed at federal police headquarters there.
Documents were seized from his home and the bank's main office in São Paulo, a source with knowledge of the situation said on condition of anonymity.
In Brasilia, police arrested ruling Workers' Party senator Delcidio do Amaral, a veteran lawmaker who is close to former president Luiz Inacio Lula da Silva.
Amaral is chairman of the Senate's economic affairs committee and a key figure in trying to push President Dilma Rousseff's unpopular austerity measures through Congress.
He is among 50 Brazilian politicians under investigation for allegedly taking bribes in the massive kickback scandal at the state-run oil giant known as Petroleo Brasileiro SA (SA:PETR4), and is the first sitting senator ever arrested in Brazil.
Supreme Court Justice Teori Zavascki said he authorized the arrest because prosecutors presented evidence that Amaral had planned the flight of Petrobras' former international director, Nestor Cervero, in return for his silence.
Cervero was sentenced in August to 12 years in prison for corruption and money laundering in connection to bribes paid during Petrobras' controversial 2006 purchase of a refinery in Pasadena, Texas. Another defendant in the case said in a plea bargain statement that Cervero had passed bribe money to Amaral.
Police entered Brazil's Congress to search for documents in connection with Amaral's arrest. They also searched his home in Campo Grande, in the state of Mato Grosso.
BTG Pactual confirmed the arrest of its chief executive and said the bank was available to cooperate with the investigation. Units of the bank (SA:BBTG11) tumbled 20 percent in early trading on the Sao Paulo stock exchange.
Court representatives said Esteves had been arrested temporarily for five days, with a potential extension of five days. Amaral was arrested for an indefinite period.
Esteves, a 47-year-old billionaire, has steered BTG Pactual through turbulent times in Brazil's capital markets as the economy plunged into its worst recession in a quarter of a century.
He is worth about $2.2 billion (£1.4 billion), according to Forbes Magazine. BTG Pactual is Brazil's sixth largest bank and the largest independent investment bank in Latin America.