For years, Sergio Machado sat not just at the helm of Brazil's largest shipowner but also of the country's goal to mount a renaissance in its shipbuilding industry.
Now, the former Transpetro chief executive is continuing to play a role that could bring an entirely different kind of change to the country.
Machado's testimony, after he struck an agreement with prosecutors last year to cooperate in the bribery investigation that has swept Brazil and government-controlled oil company Petrobras, is continuing to underline the threat against the presidency of Michel Temer.
