OREANDA-NEWS. Brazilian federal police executed search warrants this morning at the offices of Brazilian steelmaker Gerdau, the latest phase in a massive investigation into corporate tax fraud.

Gerdau chief executive Andre Gerdau is now being sought by federal police for questioning about the company's alleged involvement in a far-reaching corruption scheme involving Brazilian tax court Carf.

Federal police say they have uncovered evidence of influence trafficking, active and passive corruption and money laundering by a complex criminal structure composed of current and former directors of the Carf, lawyers and the steel company targeted in today's action.

Gerdau denies any wrongdoing but says it is "fully cooperating with the federal police investigation."

The investigation, dubbed Zelotes, is based on claims that some of Brazil's biggest companies illegally negotiated beneficial tax decisions with the tax court. Police say the scheme cost public coffers around R19bn ($4.8bn).

The investigation runs parallel to the massive Lava Jato investigation into systemic fraud at Brazil's state-controlled Petrobras.

Gerdau has around 26mn t/yr of installed capacity in 14 countries throughout the Americas.