Bolsonaro’s former international affairs adviser Filipe Martins was one of four other people arrested, the sources said. A lawyer for Martins said he was awaiting access to the warrant and supporting evidence before commenting.

Relevant details about Martins from Brasilwire:

After working at the TSE electoral court until the 2014 election, Filipe Martins became an “economic advisor” to the US embassy in Brasilia.

Martins, who is credited with introducing Jair Bolsonaro to Steve Bannon, worked at the embassy for the duration of the coup period between December 2014 following the election and July 2016, when Dilma Rousseff’s impeachment was all but sealed.

According to Martin’s LinkedIn profile, he was responsible for research about the political conjuncture and economy in Brazil, in particular bilateral relations with the US, and media monitoring during that coup period.

[Martins has] been an influence on the foreign policy of the Bolsonaro government, alongside the President’s son, congressman Eduardo Bolsonaro, who was accused by a former ally of handing a dossier of leftists and anti-fascists to the US embassy in Brasilia.

In July 2019 Martins met with the head of the FBI in Brazil, David Brassanini, who was accompanied by William Popp, Deputy Chief of Mission at the US embassy. Brassanini is the main overseer of the FBI’s expansion in Brazil since Bolsonaro (and Sérgio Moro) took office, as documented here.