Brazilian trade unionist Marice Correa, sister-in-law of the jailed former treasurer of the ruling Workers' Party, or PT, Joao Vaccari, turned herself in Friday to the Federal Police in the southern city of Curitiba.
Correa, who like Vaccari is suspected of involvement in a massive bribery and kickback scheme centered on Brazilian state-controlled oil company Petrobras, is affiliated with the PT and a member of the Trade Union Confederation of the Americas.
She arrived in Curitiba, capital of the southern state of Parana, accompanied by her attorney, Claudio Pimentel, and did not speak to a group of reporters who were waiting for her outside the entrance to the Federal Police headquarters.
Correa traveled to Panama for a conference before a warrant had been issued for her arrest, according to Pimentel, who said he is confident of her "innocence."
Authorities declared Correa a fugitive on Thursday after she failed to turn herself in 24 hours after Wednesday's arrest order had been issued.
Correa arrived in Sao Paulo Friday morning, according to her attorney, who said the two of them traveled on their own to Curitiba after receiving permission to do so from the Federal Police.
Vaccari became the PT's treasurer in 2005 after his predecessor, Delubio Soares, was implicated in a congressional vote-buying scandal that erupted during former President Luiz Inacio Lula da Silva's 2003-2010 administration.
Soares was among more than a score of political figures and business leaders who were convicted of corruption in Brazil's so-called "trial of the century."
Vaccari, who was charged last month with corruption and money laundering, stepped down from his post after being arrested at his Sao Paulo home on Wednesday, the party said in a statement in which it expressed support for its former treasurer and his family.
Vaccari is accused of soliciting irregular donations for PT political campaigns from leading Brazilian construction companies; those donations, according to police and prosecutors, stem from inflated contracts that those companies secured with Petrobras in exchange for bribes.
Thus far in the investigation, police have detained five former Petrobras executives as well as owners and executives of construction companies that had contracts with Brazil's largest company, which represents 12 percent of Brazilian gross domestic product.
Around 50 politicians suspected of benefiting from the corruption scheme, most of them allies of Rousseff, also are under investigation, including the heads of both houses of Brazil's Congress.
The Brazilian construction and engineering companies suspected in the scheme, which investigators say dates back more than 10 years, allegedly inflated their invoices and split the extra money with corrupt Petrobras officials, while also setting aside some of the loot to pay off politicians who provided cover for the graft.
President Dilma Rousseff, a former Petrobras chairwoman whose approval rating has plunged to around 13 percent amid the scandal, has sought to distance herself from the corruption case and has not yet commented on Vaccari's arrest.