Illinois State Senator Martin Sandoval has stepped down as chair of the state’s transportation committee amid an FBI probe into construction fraud and corruption.

The senator, appointed to the Illinois Tollway Board by Governor J.B. Pritzker, was a key player in the passage of the state’s recent $45 billion Rebuild Illinois construction legislation, which uses money from increased gas and cigarette taxes and state gambling revenues.

Sandoval resigned following an FBI search of Sandoval’s offices and home, SafeSpeed (a red-light camera company), several construction companies, and offices of the Illinois DOT.

The FBI searched architect Cesar Santoy’s offices, too, who also recently resigned from the Illinois Tollway Board.